I am glad I found this thread, I have been wondering this myself. I live in the Charlotte, NC area and have got my fill of easier Cache's already. You might want to check before placing one though, I know you mentioned The AT, I know NC dosent allow them to be placed inside any state parks.
Also since I am new to this what are the thoughts of combining Cache types. If a Cache is multi - staged and has a puzzle or puzzles to it what is it considered?
I like a challenge so I would say make it as hard as you want to!