I've been trying to find out how to set my avatar as a post. In some forums it said that the "Set as avatar" button is under options on the left side of a screen, but I don't see it. I can't find anything in help about this too.

It has changed when the software running the Hub changed. Now, you have to click My Account in the top bar, then Change Avatar, and upload an image. You can't set it directly from a post, unless you download the image and crop it yourself.

It's a tradeoff. On one hand, more flexibility with your profile pic. On the other hand, on the old site I found interesting pics I missed when they were first posted through people's avatars.
I thought the requirements that avatar images be SFW was weird considering what kind of site this is.