OR you could try the RC, and see if it helps out with issues #2, #3 and #4.
It shouldn't take too big an effort, even if you lose the option to read html for a while.
In that case I'd advice you to:
- make a backup of all files in your internal memory
- format the internal memory as win 7 wants you to do (to address issue #5 and maybe, maybe #2)
- install the RC
- restore books and dictionaries etc - but not system files obviously
- ask PB to send you a new battery cover, so to save on return postage
If the RC doesn't pan out, you can always revert to 15.2, and hopefully lose issue #5.
Ofcourse if you feel unsure or unlucky, you may do better to wait for the final version of the firmware. Other than the mentioned incompatibility of minor formats, and one crash to 'mainmenu', I've had not had a single problem.