Don't look at the boom ..fly formation with the tanker , remember that in the f 15 has the refueling "hole" on the left side not right in front of you so it's slightly harder for the first time.
Now with our current AI system, you must be careful because sometimes the AI boom operator does nothing even if it's in the ideal position so take a quick look at the boom from time to time when you are close and you get no contact. If the boom operator is having a beer instead of dealing with your f 15 , go back and reset the boom.
Be careful where you stand and how high from the tanker you stand ( after refueling the AI suddenly drops the boom down so it can kill you (you just blow out of the sky because the upper part of the boom is collidable.)
One thing to avoid this is to be slightly lower than normal and fly formation slightly on the right side of the tanker. Remember the first 2 or 3 times it's hard .. after that it's easy as pie.
If you feel that you can't control so many aspects like altitude etc , use altitude stabilizer autopilot when you have reached the optimal altitude and go from there.
Another thing but i guess that you already know this if you made air ref in the a 10(did not watched your vid, no time :(), micro adjustments on the throttle and very careful with the rudders!
Keep in mind that the F 15 has more powerful engines so the micro adjustments that you made in the a 10 are 2 much on this bird also when you are going to be full of kerosen the plane will be little harder to control (especially when you have 3 bags) so you know how it goes with DCS ....PRACTICE PRACTICE PRACTICE.
After you have coupled with the boom, take a reference point (ex: tanker's engines) and keep them still on your monitor; if your speed is a little lower or higher than the speed of the tanker, the boom will disconnect due to drifting away or moving forward too much. The same goes for lateral movement.
One thing i use is to lock the tanker in TWS and read the speed difference between the 2 planes .. it must be 0 if the speed goes to -1 you are too slow and you must add power and so on.
I hope that all this helped you at least a bit, sry for my bad english, good luck.