you can and will get service fees for withdrawals if you're using an atm that isn't your bank's.
my recent experience with wells fargo was that when my balance got below a certain amount, they began hitting my account with more fees until they said I owed them money.
[MOD EDIT] banks, IMO. I carry more than you have on you at times and never get robbed. my wallet never leaves my person, even when sleeping.
if you're worried, buy or make something like a money belt and keep your money on yourself. keep a small amount in your wallet, the rest stashed on your person somehwere. never stash money in your pack. I've heard about people driving away with packs when the hitchhiker gets out. never happened to me, but I always leave the door I'm exiting from open while I take my pack out.
just all my opinion, do whatever feels safe for you.
All mankind is divided into three classes: those that are immovable, those that are movable, and those that move.