This is all hypothetical until my computer arrives, but people who've used both, what (if any), are the significant differences between Firefox and Camino for OSX?
Both Firefox and Camino were giving me some stability troubles in Tiger, just as a warning. I've switched back to Safari for the duration. Give Safari a try before downloading the others and see if you hate it - it's really speedy, and if it loads all your websites and you don't crave something specific in Firefox, you might find it's better for you.-
Steph: the main advantages Firefox and Camino have over Safari are the Gecko rendering engine, which is more likely to be supported on custom websites (like the one I use to sign up for courses here at Tech) and increased flexibility due to the whole open source nature of the products. Within the two, Camino is a native Mac OS X application, so you get things like Services support (which I love), whereas Firefox, not so much, but Firefox has all those fancy-pants plugins that some people really love, like the Deepest Sender LJ client.
Really, it's all about getting which features you want.
Re: Azureus - I've had no problems with the upgrade, but I use a specific tracker only. However, I have heard that upgrading to the latest Java is a really really good thing to try if you're having troubles.