Hey @Matko!
In regards to physics, because Armory uses Bullet, it should be able to handle both basic car physics and destructibility, but you might have to write your own logic for complex mesh destruction ( here is an example of convex mesh break algorithm of some sort ).
Armory is missing some Bullet bindings that it will need for different applications, but I’ve got a work-in-progress effort to automate the physics bindings; I just have yet to find the time to finish it. You can also add them manually without much work.
As far as AI capabilities, Armory doesn’t really have anything out of the box. You’ll have to implement that yourself, or find a Haxe library that somebody else has made. The good thing is that you are completely free to develop it yourself and there isn’t any lock-in to a certain way of doing it ( although you’re probably really going to want it to be written in Haxe to save you the work of binding it with C/C++/JS ).
I don’t know that there has been a whole ton of testing to benchmark how well Armory handles that kind of stuff, but it does have scene streaming to load objects as they are needed and it has LOD support, so the foundation is there, and you could add your own logic to spawn the objects into the scene however you want.
Armory seems particularly well suited for that kind of thing as it has a lot of post-processing options out of the box ( AA, AO, GI, SSR, Motion Blur, HDR, etc. ) and has ways for plugging in your own custom ones. You should be able to do whatever you need there.