Last time I checked a bad CV axle won't cause your wheel to fall off, it may sieze up and gernade on you but that would take alot of heat and a whole lot of abuse before anything like that would happen.
As for the noise, what kind of noise is it and when do you hear it?
The rear brakes should be replaced along with you're axle seal first as that's probably the most dangerous problem you have, then assuming your axle is causing the noise up from and not your bearings.
As for your clutch issue it sounds like you have a warped flywheel and bad clutch disc/pressure plate probably caused by your leaking fluid line. From the sounds of your question this repair may be a little beyond you mechanical skills so i'd leave this one to someone who has the right tools for the job unless you have someone around who can help you when you run into a problem.