I personally haven't noticed this at all but my only hypothesis for it would be that people remember user's faces/personal pictures and remember how they view them and what their usual answers are like. People then can build friendships and people often give MHO's to friends. I guess people like putting a face/distinct picture to a name.
I haven't observed that. I guess I haven't looked close enough. But definitely after this question I'll start paying more attention to that to see if I agree with your observations. If you observe that to be the truth then there's only one logical guess one could make why that is. The people giving it are trusting more when someone reveals their identity, and/or maybe they attracted to that person so they give it.
Simple: It seems like all the guys in here are looking for girls who have sexy pictures as their profile picture. But when you post a simple photo or something not sexy no one give a shit about you. You have sexy photo they will select you as the most helpful even if you don't deserve it! And you will have many followers and a lot of private messages too.