Archer.xd

Hey, first of all welcome onboard 🙂

- Using MSAA and SSAA at same time is not a good idea. If you are playing the multi-threaded client, SSAA does not have any effect, but in any case, it should be disabled because its very inefficient and outdated.
- Tune down your preload radius to max. ~30k
- Set at least 32gb pagefile on a SSD. Your problem is likely either disk or ram, or both. Make sure DCS is installed on a SATA or M.2 SSD drive. HDD will give you overall horrible experience compared to SSD. Since you have 16gb ram, I would go for more pagefile. But if you want a smooth experience long-term especially for multiplayer, you should upgrade RAM to 32gb.

Also, if you send a log file it would help us go deeper just in case. 

How to send log : Go to C:\Users\Username\Saved Games\DCS\logs, then grab the latest text file, named either just "dcs" or "dcs.log"
How to set pageilfe : 
 

That is not a bug, when you get a warning with engines it'll overlay eng page over whatever you have at that moment. Similarly ASE page will be overlayed if you have a warning from there. Manual reference : null

This isnt related to F-15E. AIM-120 will struggle against maneuvering targets when its relatively slow, usually if below M 1.7-ish. In your tacview file its not going through the target, its clearly missing and thats mostly because it lost lock seconds before predicted impact time and lost a lot of energy when it reacquired.

40nm is a long range shot for a target that can maneuver and will. You can prevent the behaviour by simply firing at closer ranges. 

There are a few issues reported and already being worked on. ACM modes will struggle in lookdown conditions and/or if target has ECM on. You are not doing anything wrong, best is to wait for fix.

You can toggle NWS on/off as usual. (UnDesg/NWS switch to engage - paddle to disengage)
And normally for NWS HI you hold down the NWS switch. But if your wings are folded, this becomes a toggle. Meaning you can toggle NWS HI by short-pressing NWS switch once. Disengaging NWS is same, you need to use paddle switch for it.

Have you tried running a full repair and removing the user mods?

Thanks for the track, the reason is speed. In your mission units initial speed is set to 12 knots but rest of the route is 4 knots so they slow down. And your radar cant detect that kind of movement.
In your scenario I couldnt get the radar to spot them if they were below 9 knots. So you need to adjust their speeds for the rest of the route. 

Not possible, only the aircrafts placed in the same group from the mission editor can be in the same flight. And you can't mix the airframes in the group.