for battery life, I suggest going to the stickies and downloading GT2L's cleanup cab for 6.1. It will maximize your battery settings, get rid of push internet, etc.
I thought arkswitch was more for 6.5 than 6.1???
I wouldn't upgrade to 6.5. Too many lag and freeze problems with the stock ROM. I would play with what you have, maybe try mobile shell, then go the custom ROM route.
http://www.ppcgeeks.com/forums/showthread.php?t=88640