AP Renewal in Embassy(India- Chennai)?

[Svee]

My family is planning to travel to india. If kids adjust with the local schooling etc they will settle down there itself...no more coming back to USA....paves way for me to eventually moving back.They do have a valid AP recently renewed ( valid till May, 2013)

Question:

1.Can they apply for AP renewal in Chennai embassy ?
2.What time frame should apply around.... Dec 2012 or Jan 2013?
3. After applying in embassy, if we hear that the process is risky/timeconsuming, can they travel back using existing valid AP so as to enter before May 10th 2013?
4.As they would out of country for close to 6M+ .....11M...Do you forsee any issues at Port of Entry?
5.Anything else they should be aware of?
6. What else should they carry with them before they leave USA? (other than 485 ,140 receipt,131 form,PP,Check Book,)

TIA

[Svee]

Just to add: Kids are growing up... no hopes for GC(EB3)/stable job here...Better to move back when they are still young and adaptable