1) Possibly more scannable for the people who only have a few icons. For those like me who have A LOT it's very unveildy to have to scroll up and down all the time.

And related to that, I can see from comments below that you've tried to fix the mis-alignment between checkbox and tag. Many of mine are still horribly misaligned though.

4b) That's too bad. I only used it for one mod account but it was really handy to have. And no, you couldn't set icons but tags always worked for me.