you're probably not approaching safely is all. falcos tend to shield less then most other characters, that might be the only reason you do better. if you're hitting lots of shields and getting punished or pressured for it, then you have to learn how to retreat safely. the 2nd part of hit and run is run - learn how to run away, not just approach.
fair is your bnb if you want to hit and run really...it has the most range out of any aerial. you can't hit and run with tilts and grabs, so if that's what you have in mind while playing you'll probably end up using tilts and grabs at stupid times because you're not focused on when you should actually be using them.
against campy characters, why would you camp back? unless it's snake with his stupid stage control then you just have to wait until you see an opening, but otherwise you have to adapt to their style. also you said at the top you'd rather hit and run (which is aggressive) but at the bottom you say you play better defensively so I guess you're just trying to work on your approach game in general so you can mix it up in tourney? that's a great way to go about things but like you said you need lots of experience with mk if you're going to learn how to change your playstyle on the fly like that.