Oh, I get it with lasers/etc. It's because theres not enough power when you fire/causes issues.
You need to increase
[race] MissileBatt 1 2 2 7500 none none fuel*110 [nr]8005
[race] MissileBatt 1 2
10 7500 none none fuel*110 [nr]8005
The more power you use (Bigger modules on the missile) you need a larger power supply. Nothing extreme else it will never lose fuel for some reason (I believe its' been fuel * power for max fuel but in this case it might not be like that).
But if you look at your missiles, they have 0 power, thus they can't turn, (Because the modules would be inoperative). I'm guessing if you can find a propre value you can get 'fancy' and have it lose power too (Making like a homing missile for a couple seconds then stopping), but who knows. Not interested atm since its so wierd.
Increase this. The reason why stuff propells it away (like torps) is because it torps/etc can move/destroy missiles , and its alot more apparent because the missile doesn't try to relock the target or adjust because there is no power. It's basicly like you getting hit with a rapid 2 for example and the velocity pushes you

Make sure you have enough power for your missiles. In the future ill make modules you can only 'use' in missiles by toggling a switch but for now this is fine

0 power as in depleated power since the usage of the 3 modules attached to the missiles use a larger then '2' amount of power. Just remember that missiles are similar to 'ships' and require power to turn/sensors/etc.