I can only suggest finding out why you need admin privs to get Kazaa working. If there's any problem with Kazaa itself you will be in a lot of trouble. Maybe your account doesn't have write permission to the incoming folder? Kazaa shouldn't need any admin privs.

If you run everything by using 'Run as..' as root/admin you would still have the same kind of protection as you would if you logged in as root/admin in the first place. So this will NOT help you prevent virus/trojan infections. Installing a good virusscanner, keeping your system up to date and running everything on a limited account will prevent it (or atleast limit it's 'reach').

All in all it's a bad suggestion.
No offence, but your wrong.

Every time i try to run kazza from a limited account, the downloads will fail, but when i run it as root the downloads succeed.

Look, when you run kazza as root from a limited account and you happen to download a virus/trojan it will not be able to execute. If you are running kazza soley from a admin account and you get a virus it will in most cases immediately cause damage to your machine. I think your a little confused about this sirdice. You can't possibly try to tell me that running programs from a limited account as root is a bad suggestion. It is a safe practice, and it keeps everyone on the net safer in the meantime.

If you run everything by using 'Run as..' as root/admin you would still have the same kind of protection as you would if you logged in as root/admin in the first place. So this will NOT help you prevent virus/trojan infections.
True, if you have a virus infected program and you run it from a limited account as root then indeed you will harm your computer. That's not what i am referring to, i am talking about while using p2p programs it is always a good idea download files from a limited account. If you cant see what im talking about then i don't know how to explain it to you any better.