My opinion on the whole thing:
If it's to be added, it should have to cost 2 credits, only damage people within ID range of the body, and do 80 damage to the person who is IDing the body, about 20-50 to people around the body if it explodes, and the person IDing should have 5 seconds to cut a wire before it explodes. When someone is trying to defuse the C4, no one else can examine the body. The person defusing the C4 shouldn't be able to exit the defuse menu. The C4 should be the size of a grenade and placed into the pocket in the jacket or in some area that it is visible, but very hard to notice (you wouldn't notice it from a distance). This could even just be a small bump in the jack or something along those lines. The C4 also DOES NOT HAVE A TIMER except when someone examines the body, which gives 5 seconds until the body explodes. To prevent players from picking up the body and moving it from harm's way once the body is being examined, the body should not collide with props or be able to be lifted or moved in any way.
IMO, that's the only way that it will work and be fair. It has a lot of IFs though, because a lot of that would, I imagine, be difficult to code and to have work, and there's a lot of room for error. It is a good idea though, if possible, and would make TTT much more interesting and fun. It would be nice to have some more semi-original concepts to RND TTT as well.