D-Ultimate Unlocker - answered milions of times, I know

It was answered milions of times, but just to make sure, there's one question I couldn't find:
(K530, DB2020, CID53, R8BB001)

1. Is it downgrading it completely, EROM CID, CID in GDFS (I know OTP can't be changed) and FLASH CID (or do I have to manually write CID52 Main later?)

2. It's unlocked, so I just select RED CID52 and No lock change? And that's 0.33 log?

3. Can it mess up GDFS?

4. Do I have to buy more logs to backup&restore GDFS?