Not sure on the first.
Can't do the second. Once it is turned off, the WiFi is disconnected.
If you mean "keep WiFi active while the screen goes black, but the device is
still on": The feeling is don't bother. The amount of battery that the
screen uses compared to the WiFi means you don't save anything by having the
So, you can turn the auto-shut off from 5 minutes to never, and that way the
PDA will stay alive, and the WiFi will stay connected: BUT the battery wont