Realistically speaking, you're not gonna damage something like an EVO drop bracket to the point where you'd need to remove the arm and reinstall it on the factory mount. The only brackets I've seen fail are the AEV JK ones. That being said, IF the bracket were to fail, it'd be pretty tough to install the control arm onto the factory mount out on the trail. Not saying that it can't be done, it'd just take some know how and a LOT of effort especially with the springs and opposite side control arm still being in place. The bigger problem with drop brackets is that they can get hung up on obstacles and can get bent/damaged to the point where removing your control arms in the future can be difficult.
This is correct. New adjustable control arms will NOT correct suspension geometry, it'll only allow you to reposition your axles and set things like caster and pinion angle. That being said, with just 2-2.5" of lift, the amount of geometry change really isn't enough to significantly effect your ride quality. Or I should say, not in my opinion anyway. Of course, ride quality is 100% subjective.