Update: I had a possibly corrupted recovery or boot image, likely the latter. Sad to say but reflash the stock recovery and boot.img using adb, clear the data and cache using the stock recovery you just reflashed and then reinstall your apps. Much better now.
I hope I can soon give a thumbs up on this tablet as it's a good bargain for $199 via ebay.
In short, try ADW Launcher. Mine improved GREATLY.
Also, try freezing the AT&T apps you don't need. I got mine open box no contract, and I use WiFi or tether to my T-Mobile phone so I don't need or want most of them.
I just tried this today, so testing is preliminary. Hardware torture tests seem to be working fine. Mine passed a 7+ hr CPU torture test. GPU is passing the torture test too.
Most of the FC's IIRC were on launch, so these symptoms make sense.
Will try to follow up.