Agree... You shouldn't be able to jump if you're surrounded and it should reduce your (entire) movement bar when you do it.
(And maybe we should be able to move a little bit more during combats)
Or you know, just let Jump provoke attack of opportunity and see if you feel like jumping anywhere when surrounded

No, because jump isn't only a problem for AOO.
It's also used everytime by everyone during combat just to move a little bit more. Characters are frogs ATM if you're using the game mecanics.