FireFox Extension's

I’ve been a FireFox user for over six months now, and very happy with it.
I’ve no problem with the plugins,they are all from reputable software companies. Such as :
#Macromedia Flash Player,

Apple QuickTime

Real Networks RealPlayer

Windows Media Player

Adobe Acrobat Reader

Sun Microsystems Java Plug-in

But the Extensions seem to be developed by individuals . Is it risky to try these little add-ons, is it “use at your own risk” ?
I’ve had no problems as yet really except I changed from the Default (Browser) Theme , and tried a "custom built " one by some individual, which looked great but got rid of it after it kept freezing up .
The themes and extensions are listed at the Mozilla site so it’s easy to assume they’re certified for use by Mozilla for FireFox.
At the moment I’m using I.E. view1.2.4 extension. which is great for switching to IE, when I need , but I’m a bit wary of all the available extensions , and themes.
Any advice FireFox users ???

Well I’m probably the reverse 0 plug-ins listed in my Options Downloads, Plug-ins, but flash still works I remember installing it but it doesn’t show up in the list.

I have 22 extensions and 0 themes. I check out any extension I’m going to try first, there is usually enough feedback or on word of mouth.

The best thing to do is only install one extension at a time and after a period of testing/stability another and so on. There are some that I couldn’t do with out, SpellBound for one, DictionarySearch, Translate, AdBlock, Cookie Culler, FlashBlock, to name my absolute essentials.

I would star with those on the mozilla.org extensions area for the reasons stated before branching out into other mirrors and extension locations and follow the same advice on research and test only one at a time.

Thanks DavidR , I appreciate your advice .

Your welcome.