You're quite welcome!
Backing up is quite a story. Everything typed here in posts, the member list, the calendar, and everyone's PMs, are stored in the MySQL database and can be backed up with the click of a button. That's the easy part. I try to remember weekly to optimize the database, check it for errors, and download a copy. Amazingly it's not quite a megabyte yet!
All the attachments and all the modifications made to the default theme (lots) can't be saved easily. The attachments folder is where every file/photo/avatar is stored, and all the filenames are encrypted. Not much encryption to them other than a file that used to be named "photo.jpg" once uploaded as an attachment becomes something crazy like "176_photo_jpg39e1df28d45d103971f77f13ae262c2a". The database remembers that it renamed the file as such. If the database ever got corrupted, the linkage would be lost and all attachments would be scattered.
So basically, posts are safe, forum look/layout is somewhat safe, and attachments/files/avatars are not very safe.