Thinking of flashing a ROM on to my GS3. Which one is the most stable?

Hello Android Army members,

As I have mentioned in my previous forum post, I switched from an iPhone 4 about 3 months back, and I started browsing xda recently. I rooted by device and installed clockworkmod on it yesterday and i am thinking about flashing a new JB rom on it. From what I read on xda, the AOKP rom by Task & Ktoonsez seems to be the most attractive one. But I have a few questions, and being a noob, I am a little apprehensive about posting it in xda, so thought I would post it here first.

1. Should I flash at all, or should I just stay with the stock Touchwiz? I want a stable phone, but JB is very tempting.

2. When I try to backup with clockworkmod, I get a "Not enough space" warning. Any workarounds to this?

3. Which is the most stable ROM out there for the ATT SGS3? I like the look of stock ICS over Touchwiz ICS (I am using Nova Launcher, which gives me that stock ICS look)

4. Will I miss anything that is there in Touchwiz if I switch to a AOKP ROM? I have never used a Galaxy Nexus, so I don't know what features are of Android and what are Touchwiz dependent.

5. Will I lose my data by flashing? Any way to avoid losing data?

Thanks in advance!