Yes - use any USB port.
If the iPod Touch somehow has a virus in it, it could transfer it to your computer if you plug it into your computer, even if it is just for charging.
Yes. You charge them by plugging them into your computer in the same way you would to add/remove songs.
To charge an iPod Touch, use the USB cable that comes with the iPod. Charge by plugging iPod into a computer.
By plugging in your ipod to your computer.
No
It seems as though you are nut plugging in your iPod Touch properly. An iPod Touch will not lose battery power while plugged in. Either that or you are plugging it in with a faulty cable.
Yes, if is says it charges it, if you don't know then try plugging it in to it
Use the cable that came with the iPod Touch to connect it to the computer, and the iPod must be on for it to charge.
plugging the ipod to your computer and open itunes, it should prompt you about the update
Try plugging the iPod into your computer as you would normally charge it. If this does not work, hold the Home button and the Sleep/Wake (power) button simultaneously for 6 seconds, and then see if it turns on. If it does not come on, something might have shorted the iPod's circuitry.
for a computer to charge an ipod, the computer must be on
If you plug your iPod into a computer or wall adapter, you can charge your iPod Touch.