H1B initial start date 10/01/2006. CANADIAN citizen, still 6 month left in sixth year and I-94 expiring on 4/24/2012. My employer about to submit for 3 year extension. But PD-May 29 2008 ported from previous employer, current now. What are the option??

1.Apply for h1b extension NOW and apply for i 485 jan 1 2012.

2.Once i apply for I-485 on jan 1 2012,can i go next month out of conuntry for two weeks from Jan 4-18 (i have I-94 valid until 4/24/12-no visa) Or do i need advance parole.

3. After submitting I-485, Will i get h1b extension if i apply before 4/24/12. If so how many year i will get extension.

4. What is the best date to submit I-485 so wont be subjected to rejection on ground of earlier submission. Can i send Dec 31 2011 to reach service center 1st or 2nd Jan 2012 ?.