Actually, the answer is, maybe.
Look at 8 C.F.R. § 316.5(c)(1)(i), The answer is there. Departures of more than 6 months and less than 12, do not necessarily break the required continuity, but the burden is on the applicant to establish that you did not, in fact, abandon residence in the US. Be prepared for a prove you didn't break continuity under the regulation. You can show maintenance of ties with the following facts (this is not an exhaustive list):
(A) The applicant did not terminate...
No more than a year if you don't have a reentry permit, but you can stay outside the US for up to under 2 years if you have a reentry permit. note that a reentry permit doesn't guarantee readmission, but it at least protects you from abandoning your GC. Speak to an attorney for more details about this.
No, but you mom's spouse can file a petiton for you as his step-daughter if the marriage took place before your 18th birthday. If the marriage took place after your 18th birthday, you will have to wait until she gets her citizenship (she can get it 3 years after getting her green card), then she can file a visa petition for you, even if you are considered an overstay. Of course, you can also opt for adjustment of status if you get married to a US Citizen as well... There are risks in remaining...
I don't see any reason for you to withdraw the adjustment of status. Just apply for advanced parole. Also, if your adjustment of status is pending, it doesn't matter if your OPT has ended. Since you are a victim of domestic violence, a VAWA petition may possible, even if you intend to remain in the marriage. Of course, you can't file AOS on the VAWA while your AOS on the marriage petition is pending.
Yes. Your husband's employer can file an L1 extension 6 months in advance of the L1 expiration. The extension is filed with USCIS with form I-129, including all necessary supporting documents. At the same time, your L2 extension should be filed in the same petition package with form I-539.
Note that there is a 5 year limit to L1B and 7 year limit the L1A status. In some cases, it is advantageous to change to H1B if you intend to stay long-term, and have an employer willing to sponsor for a...
As long as your change of status is pending, you're authorized to stay in the US, but you'll be reaching 6 years in September, so USCIS won't be able to extend your H1B past this date.
To answer your question, if you don't receive your new I-94 by August 22, 2010, you can still stay until a decision is made on your case. I wouldn't stay longer than the time you'd reach the 6th year limit.