Can they lock you out of physical usage of the Kindle, like a remote kill-switch of sorts? Scary, if true..

Fair point on the software improvement though -- you might want to look into Duokan, it seems to be really popular and adds native ePub support: http://www.mobileread.com/forums/showthread.php?t=150175 (bonus if you like some aspects of the original OS: there's a tool that let's you switch between the two firmwares.)