Thanks for response guys. I think I solved my problem with ESC heating by adding separated UBEC (3A/5V). I also added wire to battery and put my ESC where the stock one was (motor holder). Running without BEC my ESC is now just warm after flight, great! I also replaced elevator and rudder servo with 939MG metal gear servos and added AC hinges to all control surfaces.
But now I have another problem
First of all, my first flight (before above mods) was with receiver and ESC in front of fuselage and with 2200mah 3S lipo and together that was about 260 grams of weight in front for let's say, good CG. Now I have ESC, MG servos and receiver in back of the plane and in total that is about 100grams of weight. I tested it today and I needed almost 120 grams (plus 190 grams 2200mah 3s) of weight in front for plane to GLIDE straight!! What do you think about that? I think this is good counter weight to be again in good CG. But I'm not quite sure that I achieved correct CG. Why?
When flying with almost full throttle and what to make low high speed pass I need full elevator down to actually go down with plane so this can also mean that my CG is still now good because the plane still wants to go UP.
The biggest problem is - my plane goes RIGHT when I apply throttle!
Without throttle it glides very well and stable but with throttle it goes RIGHT and UP like it's still tailheavy and I need almost full left aileron to return it back in line (and hold it). I attached the motor angle image (looking from behind its about 5 or little more degrees left) so please tell me if this is good or not and if the motor angle can be the reason for my problem. I manualy pushed down right aileron using clevis and it's better now but now my aileron is 5mm down in idle position and I'm now sure if this is the right solution
Total plane weight with (with additional weight for correct CG) is now near 1.4Kg. I will replace that 120gram dummy weight with FPV gear but first I need to solve above problem!