I have the Tapatalk issues too... though I found if I rotate it to landscape, then rotate it back, it's back to normal.
I am getting duplicate emails too... but only when I have iCloud set up to deal with mail... and I can't click them for the life of me to mark them as read haha. I take mail out of iCloud and it's fine.
Facebook is buggy as heck, so I'm just using the mobile site, which is fine!
I restored my iPhone to iOS5 with my backup, and if I go to Settings to choose my wallpaper, I have none in the default wallpapers folder... it's blank. I dunno if the two are related, though.