I hold an US Green Card and had to stay out of USA for 2 yrs. I applied for reentry permit & left USA in APR 2009. My re-entry permit expires on 23 APR 2011.I have the following queries about re-entering US and applying for a 2nd reentry permit

Can I travel back to USA after 21 APR 2011 (say 01 May 2011)? What questions can I expect from the immigration officer. Will my GC be active for another 6 months if I stay in USA for 2 weeks and again go out?

Once I return back from USA, can I apply for a permit from outside USA? If not, can I apply while in the US. In that case, do I have to wait till I receive finger printing notice and how long does it normally take to get it.

What is the best way to maintain my GC,given my situation to have to stay out of USA for another 4to6 months?