I'd like to setup multiple operating systems and FF versions to
automatically install, apply updates and run unit tests, etc.

This is what I'm currently thinking....I'd love to get feedback and
find out how to do this better. My priorities are (1) test quality,
including breadth (2) time, as in i'd rather spend my time writing
tests than setting up a testing framework, and i'd rather be writing
features than writing tests (3) not spending too much money

1. buy a cheap physical machine running ubuntu
2. run windows in a virtual machine
3. on both ubuntu and windows download a few version of FF
4. ??
5. write script to "install", "upgrade" and "uninstall" my extension
by copying files into Profile. script opens FF--somehow click
"ok"??--- reads prefs.js to see that the right thing occurred.
6. ?? navigate to extensions automatic_test_suite url, read logs

The more realistic the better, such as actually clicking our
"download" link, which calls InstallTrigger via Javascript

Thanks for the help,