For the temperature thing, I found this to be a problem if I reflashed a rom and it kept old settings. It would keep the settings for cLock, as I would go in and metric would still be unchecked, but I think it always needs to be cycled to work. Just go in to settings and hit it twice and see if it works... or use DashClock
And the battery dropping when the phone reboots... I think that's merely an issue of the way the phone reads the data. I imagine it can read the battery level better once it's been on for a while. Rebooting kinda refreshes everything. I don't know how accurate I am with this, but I don't THINK it's anything you can do anything about. If I'm within my last 15% and reboot, I usually come back to find like 8%.