1. No change list. If you make one up, please share with us.
2. No ramifications. Your boot-up splash screen never changes. Ever.
3. Yes. Do a prior Desktop Manager backup first for safetly
4. No. Routinely your device will be restored with ALL settings, emails, etc., just as before. Glitches do occur, it is not a without fail process. But my guess is 98% of users get a clean upgrade.