First off, see the announcement in the Rules/Announcement forum. That has a very basic explanation of what happened. I'll try to read and answer as many questions as possible. But I'm also running behind on other things, partly because the forum technical issues have absorbed a LOT of time over the last few days.
1.) Avatars: You will all need to upload new avatars. We saved the user database. Avatars were not salvaged. You will need to upload them instead of linking. If you are having a problem uploading an avatar, it may very likely be too big. Try scaling it back.
2) PM's: PM boxes allow a limited number of messages (50). So make sure to clean out your inbox from time to time.
3) Themes: I hope you like the main forum theme. It is a bit basic. But given all we had to deal with, cool graphics and other things that make it pretty were lower priorities than combing through the database to see what we could salvage to get us up and running again. Currently, your options are the standard dark BCSL theme and a blue/light theme that is fairly low profile for those browsing in places where you don't necessarily want the world to know you are browsing. More themes (lighter) will likely be coming soon.
4) Profile settings: You should all thoroughly examine your profile settings to get your accounts set the way you like them (notifications, time zone adjustments, theme features, etc...), since most items were likely re-set with the new installation.
5) Other bells, whistles, and doo-dads: Feel free to still suggest things you perceive as forum improvements. Right now, we are pretty stripped down. I will be adding some, but not all, features back in slowly and carefully. Not sure at this point what is coming back, what isn't, and what will be new. Time will tell.