Possibly have different AP for different tabs?
I don't think so, I think you should get 2 AP for the reviews/comments. And then 2 AP for the walkthrough/help comments, that would increase for every so many "good advice" ratings that you get.
So if you post and answer and your get 30 "good advice" ratings. If you get 1 AP for every 10 "good advice" ratings. You would gain 3 AP in addition to the 2 AP you received just for posting. I hope that made sense.