I'll bite.
NoScript: disable scripting and enable it selectively using the F12 "site preferences" shortcut.
AdBlockPlus: You can get various urlfilter.ini if you really want to. I really dont need this, just block the most annoying ones with right-click:block_content. Some sites need the "normal" advertising, and once you block the top-10, you don't have much to complain about. Anyway, I will give you that point.
Flashblock: Here. Myself I just "enable plugins" (F12 again) on sites I want. *And* you can block the flash content with the normal "block content" too.
Firebug: Meh. Have you worked with dragon fly?
RefControl: Hmpf. F12, disable "send referrer information". Maybe it is just me, but I never needed to spoof referrers.
And yes, I use every one of these extensions on firefox, because it is not there as default. And some more. In a *memory-limited VM* just so it does not goes haywire and swaps the hell out of my current apps to oblivion. Lucky me.
Comparing information and knowledge is like asking whether the fatness of a pig is more or less green than the designated hitter rule." -- David Guaspari