brain trust: Firefox 7, 8, neither?

Dear LJ brain trust,

Upgrading a browser is a dangerous thing because you never know what'll happen to your add-ons (or UI experience in general, really) until you get there, and rolling back isn't always smooth. In the past I've used my iBook to test-drive new versions of Firefox before committing on the machine where it really matters, but apparently OS 10.4 is no longer good enough for Firefox (and the iBook isn't good enough for newer operating systems, which I knew when I bought it).

I was hoping that I could just visit the pages at the Mozilla add-ons page for the add-ons I care about to find out the latest versions of Firefox on which they're supported. No dice. I can apply Google one at a time to look for evidence one way or the other -- for example, I found a Stylish user script to change something in the Firefox 8 UI, which suggests it works with Firefox 8 -- but is there a better way?

I know some of you are already using Firefox 7 or 8, so just in case there's overlap in our add-ons, I'd appreciate it if you could let me know if you have direct knowledge (and for which versions of Firefox) for any of the following: AddBlock Plus, Flashblock, Ghostery, Greasemonkey (I assume, but...), HTTPS-Everywhere, Image Zoom, NoScript, Stylish. I use others, but these are the important ones.

Thanks.

PS: I'd also appreciate hints about major UI changes.