Here's mine: When online, it would of been nice to have some sort of area ''general chat'' where people in that zone could chat with each other while clearing or even ask for help ( ex: '' SL XX looking for help for (insert boss name here)anyody interested?''). And maybe, if you're the kind of person that thinks the first playthrough should be alone, it could only be available to NG+ or be unlocked after defeating Gwyn the first time.
Anyways , just something that crossed my mind , i can't wait to read your ideas!