I looked this up in the vBulletin manual and I think all Go Advanced does is take you to the regular "post reply" screen. So you can click on "Quick Reply" within a post to activate the quick reply text field if you want to just stay on the page and reply. Or you can hit post reply to go to the regular reply page. Go advanced is a way of going to the regular reply page from the quick reply box. If you know something else on the topic, please let me know because I had to research just to learn that much.
I did, however, activate allowance of html code and attachments in the forum, which I think should fix the other issues. The permissions are per usergroup, per forum, so it is a bit cumbersome and we sometimes cut off permissions simply by accident setting up new forums. Just let me know if there are setting problems; I try to fix them within the day.