use juicedefender, then when you lock the phone, it will auto turn off your 3G. just download juicedefender through market, it is a free Android app

you use the apps2sd, which means that you have to partition part of your SD card to become like your internal storage, then you can install apps in your SD instead of internal storage.

wildfire got CM7 custom rom as well
try it

No, kernel is the core for any OS. In simplest term, it is the bridge between software and hardware.
All OS has kernel, and Android OS's kernel is based on Linux.

not sure if this apply to stock ROM, i have rooted and using custom ROM

what i did was partition my 1GB of the sd card to ext3 or ext4
then use link2sd, so now your phone will treat your SD card (that 1GB space) as system space

you can partition with a few methods
through
1) manual command in terminal or adb
2) ROM Manager
3) ClockworkMOD recovery (not sure if other recovery has that)

we partition it to ext3 or ext4 already, so windows system sure cannot detect
but if you have linux system likes ubuntu or linux mint or others, then can detect the 1Gb space.