[Q] Change recovery-Rom topic

HI, i have been having isues with my asus tf101 baterry, about one month ago it suddenly charge and discharges, like: 10%-25%-40%-70%-80%-100%...I made a factory reset but nothing. 2 weeks ago, it solved alone, without do anything, and was ok for 2 weeks, now again i have the problem..
i have installed cwm recovery, i want to change to android revolution rom, to see if the problem finish:

1 question: How i change from cwm to twrp recovery? installing twrp from cwm using a zip? is there no problem?? or downloading goomanager, installing recovery script?? Is there any problem to use cwm or twrp( i have read, to instal kk i dont use cwm)?

2 question, what rom is stable to try to solve this? i see kk 4.3 etc, but i just one my baterry works ok...

3 question, is there any way to clean absolutely the stock rom? i tried wipe cache, dalvik, factory reset(again) but nothing solve.

4 question, is possible to wipe ALL including system, and install the asus stock rom using zip¿?

Thanks for your atention, please be the most specifically possible because i am new on this, and i just one my tablet for study(read books).

I have a asus tf101 b70 root, with CWM recovery is a old version 5.0.26 something..