Wife's GC - I am citizen now - few questions

[youwithvls]

I applied for I-130 for my wife when I had a GC. Now I am a US citizen. I requested (Sent letter along with my citizen certificate and I-130 receipt copy to USCIS) to upgrade the category for I-130 but I haven't heard anything back from USCIS.

I-130 for my Wife - RD = 6/19/2008.
The day I got Naturalized (became US citizen) = 7/4/2009

Questions:
(1) Should I file I-485 for my wife without waiting anything (like new I-130 receipt) right away?
(2) Should I file a new I-130 and I-485 to save time?
(3) What is an approved I-130 petition?
(4) If my wife loses a job after filing I-485, will she be legal to stay here?

Please advise.