If I were to apply a waterslide decal to the surface, let it sit overnight, and then melt the plastic for battle damage, would it warp the decal in any way?
What If I let the decal sit, put a topcoat on it, and then burned it once it was all dried?

I'm going to be doing a model where I want a decal to be hit with damage.
Like on this model:


It would be a WWII style pinup, like on a bomber, and no larger than 2x2inches.


If this is the wrong place, I'm sorry, I'm new and it seemed the most relevant.

I should watch out with melting. If the paint or decal get too hot you get fire and then all is lost. It would be better too create battle damage without heat, but use a drill or a hobby knife in combination with a paint job that shows bare metal at the edges of where the round has made an impact..

If you still want to use heat, better melt the plastic first and put the decal on afterwards and use a lot of setting solution. Depending on the damage you want on your model, maybe you can cut the decal in smaller pieces first.