Yurgon

That's a clear-cut case of "it depends". 😄
Obviously, you first need to enable the aircraft's Situational Awareness Datalink (SADL), which is very inappropriately labeled "JTRS" on the AHCP.
Once the jet is up and running and the HMCS is on, that's it.
Now, it depends on a bunch of factors.
Many AI flights will show up without a problem, including A-10C and F/A-18C (not sure about the F-16C).
For player controlled aircraft in Multiplayer, only A-10C (no matter if legacy or A-10C II) will show up, but F/A-18C and F-16C won't.
AH-64D use their own kind of datalink and don't show up on the HMCS at all, regardless if they're player-controlled or AI (the AH-64E uses Link 16, but we don't have the Apache Guardian in DCS yet).
The problem here is that SADL (used in the A-10) is not compatible with Link 16 (used in Hornet and Viper, IIRC) and needs a gateway, like an AWACS, but DCS doesn't seem to make that distinction, so in some cases aircraft with an incompatible type of datalink still show up in our A-10, in other cases they don't, and I'm not aware of any workarounds. So it's a mix of an actual real world problem together with a DCS-related problem.

There are many ways to skin the cat. 😉
When I began my journey in DCS, I didn't even bother with the altimeter, flying visually all the time. Then I learned about QFE, and the altimeter reading 0 at the runway felt perfectly natural. Plus, the in-game ATC only provides QFE, so you can easily set QFE for the arrival field by calling the ATC and setting the pressure that he gives over the radio.
Then I learned about the A-10C in particular, and that it uses QNH for internal calculations, so that the altimeter will show the runway elevation above mean sea level before take-off. I've gotten used to QNH and nowadays that's what feels the most sensible to me, because it works all over the place -- unlike QFE, QNH is not tied to any particular spot. When QNH is set, the altimeter shows the aircraft's altitude above mean sea level. It just makes sense.
With the static weather presets that are most widely used in DCS missions, QNH will also be the same all over a map, so it's basically a set-it-and-forget-it thing.
In real life, air pressure is a local thing; it can be different from one place to another and it will differ over time, so when flying from one area to another, you'd have to adjust QNH to the area you're flying in. However, in commercial aviation, above all the obstacles that we're concerned with in low level flying, it doesn't make much sense to adjust QNH every 10 or so minutes during a 3+ hour flight above 20,000 feet. Plus, different aircraft would use different pressure references, making vertical separation a nightmare.
So above a certain altitude, everyone just sets the standard pressure setting of 29.92 inHg, regardless of local air pressure, and now everyone is on the same page. In DCS, this only really starts to matter when you get into real flying procedures in realistic missions, or when flying on multiplayer (with human ATC, or with realistic procedures).
So to make a long story short, my preference is QNH; just set the altimeter to read the runway elevation before takeoff and you're good (the actual QNH issued by ATC might be a bit different and your altitude might be off by 10 or 20 feet; that is perfectly normal). Since a couple of patches, DCS will preset QNH for ground starts.
To set QNH on your own, you obviously need to know the runway elevation. You can use the F10 map and point the mouse cursor over the runway; next to the coordinate display on the corner of the window, you'll find the terrain elevation.
There's a downside, and that is you can't ask the in-game ATC for QNH for your destination airport. Once airborne, you'll have no way of getting QNH, unless you started to get creative with the radar altimeter, known terrain elevation and some math. But, as I said above, most DCS missions use static weather where the air pressure is the same all over the map, and where ever you fly, QNH will be the same anyway.
 
Did you mean QNH there?

The most common cause is when Options -> Misc -> Force Feedback is checked (set to on) for a non-Force-Feedback-stick.

You'll need to select an aircraft to match against; the process is like QuiGon said,  Air-to-Air mastermode, HUD as SOI and then DMS Right/Left Short. You can use the IFFCC Test menu to select a bunch of pre-configured aircraft in case the Mi-24 isn't initially in the list, or just use "MAN RTY" or so for a rotary wing aircraft with a fixed rotor span.
Regarding the first question, as the others already said, it takes place purely in the visual arena. Forget the TGP, there's not really any use for it in A/A mode. With helicopters in particular, if you know which spot of sky to search, you'll probably see them visually before you find them in the TGP. And if you don't know which spot of sky to search, the TGP won't help either. 😄
Just be aware that helicopters are quite the challenge for a fixed wing attacker. They're small, making them hard to spot (yes, even the fat Hind is pretty small from 2 or 3 miles out), you have to get very close for a good shot, you'll fly by fairly fast (even though "fast" and "A-10" don't usually belong in the same sentence 😉), and then they can turn on a dime and toss some angry 7,62 or even 30mm retribution your way if you didn't kill them in the first pass. Their flares can protect them from Sidewinders. But if you get the gun on target, it certainly doesn't take a lot of rounds to bring down any chopper.
Good hunting!

Awesome! 🙂
For the fun of it, you could also do the same procedure the other way around: Make Mav SOI, set it as SPI, set up TGP on the other screen, slave all to SPI, and then slew the Mav around. This time the TGP should follow the Mav. Granted, there's not much practical use for this particular scenario, but it shows how the Mav can be used as a poor man's TGP, and more importantly it shows that the system is fairly universal and not just tied to the TGP alone. 😉

That's exactly what it says. The Maverick doesn't track a target and inhibits the launch, because it would miss anyway.
To command a track, you can either slew the seeker off target and back over the target, or hit TMS Forward Short, until it tracks.
If you wanted to use Force Correlate, as the thread title suggests, instead of actually tracking a target, you'd have to move the Boat-switch out of center and back to center with the Mav as SOI (doesn't work with all types of Maverick). Be aware that Force Correlate is not very accurate, and chances are you've followed bad advice and you really want to command a track instead of using Force Correlate.

Excellent, thanks!
Your altitude was 22,000 feet below your waypoint. Due to gravity constraints, CCRP can't help you there. 😄
Set your waypoint elevation to 0 feet AGL via the Mission Editor or via the CDU, and you'll get a valid CCRP ASL, PBIL and all the other symbology. 👍

Not sure I understand the question, so I'll try to rephrase it and provide 2 possible solutions.
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a) Is it possible to fly forward and change direction without using the cyclic?
Yes, this is possible. In the Ka-50 in particular, make sure that the Autopilot Heading Hold channel is Off. While flying forward, get the helicopter trimmed so that it doesn't require any input for straight and level flight. Autopilot Bank Hold and Autopilot Pitch Hold should both be on.
And then just input left or right rudder and watch the chopper turn. Aerodynamically, this does not make a whole lot of sense, and it's slow, but it works. 🙂
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b) Is it possible to fly sideways without inputting any ruder pedal?
Yes, to a degree this is also possible, particularly in the Ka-50. This time around make sure that the Autopilot Heading Hold channel is On, this is absolutely crucial here!
Again, the Bank and Pitch Hold channels should also be on.
Get the chopper into a well trimmed hover so that it does not require any input to remain stationary.
And next, input some smooth cyclic either left or right.
When testing this, I found the chopper will keep the last trimmed heading up to 50ish kph left sideways flight and up to 25ish kph right sideways flight. Any faster and the Heading Hold channel seems to run out of authority and the nose starts vaning into the relative wind. When reducing the sideways motion and the AP regains sufficient authority, it will get the nose back to the previously trimmed heading.

Oh okay, in that case this is probably a better place to find specific help: https://forums.eagle.ru/topic/168657-vaicom-pro-plugin-for-voiceattack/

You need to hook the received target, and then hit OSB 7, labeled "CNTCO*" in red. This should clear the target from the TAD. I'm not aware of any downside; in DCS at least this doesn't get fed back to whoever sent you the target in the first place, even though it means "Cannot Comply".

Nice one, took me a bit to figure it out. 😉
 
The thing is, you have an initial point object named T6414, and you have a waypoint also named T6414.
 
In DCS, initial point objects are stored in the A-10C's navigation system as preset or predefined or system waypoints. Now if you add a waypoint with the same name, the aircraft's internal database needs to be able to differentiate between these two. The way DCS seems to handle it is to add a number to the extra waypoint, so in your mission, if you'd named it "SARAH" then the waypoint would become "SARAH1", and if it ends in a number, DCS increments that number to the next one that's available, to "T6414" becomes "T6415".
 
Unfortunately, I'm not aware of a way of setting up a flight plan with named waypoints that correspond to initial point objects and share the same name, unless you use "Prepare Mission" and set up the flight plan in the CDU itself.
 
But there are many workarounds, like naming the waypoint "WPT6414" or whatever else you can think of, as long as its name is unique.
 
Does that make sense?

The Maverick needs to actually track an object, or else it can't be launched and the aforementioned NO TRACK LAUNCH INHIBIT (I think it's a little more abbreviated) will show up.
 
Ground stabilize does not command tracking, so that's no good.
 
In order for the IR- and CCD-Mavericks to track a target, you can either slew the seeker over a target until it tracks, or command a track with TMS Forward Short.
 
Once it tracks, the tracking gate will collapse, and start flashing. If I'm not mistaken, the collapsing part is correct, while the flashing is a deviation from how it works IRL. But anyway, the Mav page will give you feedback for a good track, and then you can rifle it off. 🙂

Well here's the fun part, and I just found this out:
 
When the skill of an aircraft is set to "Client", the "FAILURES" panel is empty.
 
When you set the skill to "Player" instead, the panel is properly populated.
 
As far as I'm aware, these failures don't work in Multiplayer, which is probably the reason the panel doesn't work for clients.
 
But in single player missions, you can fly any aircraft that is set to Client, and the failures do seem to take effect then.
 
So I guess that's one problem solved: Set the skill to "Player" and at least you can see what's set and what isn't.
 
However, that doesn't explain why the failures were set in the first place when you never hit that RAND button; I have no ideas in this regard.

If the mission starts around dawn, the HMCS will be set to night mode.
 
Hit the STAT OSB, then HMCS (OSB 3, top middle), and then select day mode. 🙂