Extras is extremely useful; you'll want to take a look at what it offers.

extras-testing is moderately useful, but with some caveats as it's essentially the "beta software" repository - many will be just fine, some will occasionally explode.

extras-devel is highly contraindicated as that's the developer testing area; use it only if you're very familiar with Linux systems and how to recover broken ones in case of Bad Mojo.

PR 1.3 is a good update to install ASAP. 99% of folks having problems with it had such because of existing installed stuff from extras-testing and extras-devel (or their own customizations) messing up the upgrade process. So do that early.

Also, root access is something to be very, very careful with. It's possible to make things go boom with same. Only use root if you already know what you're doing or if you have clear instructions as to what to do while there.

Hope this helps!