I'd argue that Forked Tower is the issue that needs addressing most. The entry method has caused a LOT of friction in the community (apparently both in-game and otherwise) and has prompted a thread that has devolved into arguments that are unlikely to end any time soon.

That aside, I feel they should increase the Atma drop-rate too - I can't be the only one who found their enjoyment of the new content tarred by how awful the drop-rates are.