Number 2, in my opinion would be a definite no-no...Kudosu should only be kept within thing related to the modding process, and nothing else. Also, having some reward for suggesting something would just make this seem more like...a game I guess? There's a better reason somewhere in the abyss of Completed Requests, but really...just no overall. >:
Number 1, I'm a bit iffy on...Someone can easily abuse that (e.g. an annoying lonely, bored person deciding to invite every single person in the lobby, despite not knowing them?)