I wasn't sure where to post because I have several questions. Any help is appreciated. I have an iPhone 3GS 32GB. Have AT&T so there was no need for unlocking and am running 3.1.2 O.S.

I think it's been about two months since I jailbroke. I used this article to do so:
Tutorial: Jailbreak Your iPhone Using BlackRa1n

I also updated to 3.1.2 not too long before I jailbroke. Everything worked great. I also have my keys signed as indicated on the home page of Cydia. In addition to all this I recently downloaded ********** using Cydia by adding the *********.us repository.

My questions are:
1. If during the jailbreak I only downloaded Cydia and now want Rock and Icy can I still get them? If so how?
2. If I were to have Rock would it be pointless to uninstall my applications through Cydia and reinstall them using Rock (because I've heard it's cleaner)?
3. I recently downloaded Proswitcher and my apps seem to randomly quit now (even while not backgrounded). Does anyone know if the problem is related to Proswitcher because it didn't really happen before when I was only using Backgrounder?
4. Now sometimes when I open Cydia it gives me this message:
Failed to fetch...(turns out when I actually decided to write this post it's not showing me the message!)
I know this is because I added the ********* repository but what does that mean? A friend told me on Rock that you don't have to add it so if I were able to get Rock could I download ********** through there and stop the messages on Cydia?
5. Last question! I've been reading about the new 3.1.3 update. Rest assured I won't update. But is there anything else I need to do? What are all these new jailbreaking updates? Like BlackRa1n RC2 and such. Anything regarding me? Again: running 3.1.2 O.S., jailbroke using blackra1n, don't need to be unlocked.

Thanks guys! Sorry for all the questions. I know some of them were unnecessary.