Question on I-485, EAD and AP

[sunvinmon]

Cheers All, 
I live in US and currently on H1B. My Green card petition is under F2A filed by my spouse and PD is Sep2015. My date is current as per chart B (i.e Date for filing) for Oct2016. I am eligible to apply AOS now that will fetch me EAD and AP (adv parole) but I have travel plans in 3 weeks so i might not apply for AOS in Oct since i won't be in USA but maybe able to do so in Dec2016 after I am back. I can travel and come back on H1B so i don't have any worries. I plan to apply for AOS after i come back December. 

1. Will i still be eligible to apply AOS in December since dates were current in Chart B (DF) and USCIS indicated to follow that chart in Oct? I hope the chart doesn't mean that we should apply in the same month (OCT) it was asked for. Could you please provide insights on this? 

2. On the other hand I am under the impression that i can't parallely initiate my 485, EAD, AP and then travel on H1B in few weeks. Can i? if yes, the parallel processing will save about 2 months of time. Instead of waiting to apply in December I can do it NOW & have EAD, AP by Dec/Jan. 

3. If i am on EAD do i still need to maintain H1B when it expires? (expiring in Aug2017)?  I am under the impression that EAD is enough to work for my employer and have him not apply for an H1B extension again. Please let me know. 

Thanks,
Vinny!

[care_candidate]

Are you EB-1?