PMd, but for everyone reading
If you use something like iPhoneBrowser, you can see that the SpringBoard.app (use Go To Location|SpringBoard Images and Settings) has a DEFAULT_CARRIER_TMOBILE.png that is black, and an FSO_CARRIER_TMOBILE.png that is white.
SpringBoard switches which one it uses based on the applications normal status bar being white or black.
So, copy the FSO_CARRIER_TMOBILE.png to your PC (right-click and Save File) then replace the DEFAULT_... file with it (right-click and Replace File).
Now your carrier is always white.
You can do something similar for the BatteryCharging or Edge files.
Currently, I do not think anyone knows how to fix the time.
Oh, and for those that can't Google:
http://code.google.com/p/iphonebrowser/