Question: I'm using a tablet with Android 2.2. Is there something like `Tab` to switch to the next form field?

Answer: 
Is this what you are looking for [paid app]: <https://play.google.com/store/apps/details?id=com.vmlite.vncserver&hl=en> 

However, if you are willing to go through a lengthy process [but free], you can follow the tutorial [here](http://www.howtogeek.com/howto/42491/how-to-remote-view-and-control-your-android-phone/) to access your phone via PC.
Give [androidscreencast](http://code.google.com/p/androidscreencast/) a try. You may already need to have USB Debugging enabled for it to work, but you've said you already have that enabled, so should be ok. It just needs a USB connection to the phone and goes over the ADB protocol.