Well I don't know if I could anwser your first questions but I can anwser
Quote: "is 2d alot less challenging?"
It really depends, I mean in my opionion it is easier, but the only 3D game I've made is the one from the tutorial that comes with darkbasic.2D I find a little harder to do animation, but it gets easier with some practice.Also since I'm currently working on a 2D fighting game, all I have to make is the characters, backrounds, and animate them, and finally code.
So basically 2D is easier in my opionion, but some parts are still time consuming.
2D Fighting game in Progress