Yeah, I was checking out the FDF Mod rescource.cpp earlier (just looking for some random stuff) and I found that you can also change the compass, GPS etc. to whatever you want as well as adding more "objects" that can be animated/ used in one way or another.
Also, I found that there are loads of bars/ meters that aren't shown in-game. Like there is actually a health bar for the player, you just don't see it.