[Q] After reading a few guides, I'm still a little confused (CWM & rom related q's)

Guys I apologize for the long, and n00b post, I have no experience with this whatsoever, and this is an expensive device, i want to make the process as safe as possible, so I would really appreciate if you can help me clear my confusion.

I own S3 GT-I9300, which I want to change it's rom to one of the stock roms of my country, device purchased in Australia, and I'm having some issues.

Now, I understand I need CWM to be able to back up my phone, and Odin to install, but here is what I'm confused about:

1. There is a pack by ChainFire which installs CWM and roots your device, this is nice, however I now learned that the CF pack contains a relatively old version of CWM, and if I want to install the latest one 6.0.1 if I understand correctly, then I need to install it by myself.

- what's the difference between the new CWM version and the one in CF's pack?
- The CF pack installs root to your device, do I need to do this myself if I install only the CWM recovery?
- Can I install an 'official' (i.e. not a mod) rom without rooting my device?
- Is rooting reversible?
- Is the latest version of CWM the one which supports touch?

2. I found many links, but I'm not sure which one is considered a safe ones here so I would appreciate trusted links to:
- CWM 6.0.1 (or later?) which supports touch for GT-I9300
- Odin - the version I need

And finally, if I understood correctly the way to do the procedure itself is (roughly):

-get Odin, CWM, and rom
-put device in recovery mod, open Odin -> PDA, flash CWM, reboot
-Back up device with CWM
-put device in download mod, open Odin -> PDA, flash ROM, reboot

Is that right?