B1 extension - urgent!!!

[abc321]

Hi,
I plan to extend my stay in US by 2 weeks from the date mentioned on the I-94 (ie 28th Aug). I have not yet submitted my I539. My questions :

1. What are the chances of getting a response from uscis before 28th Aug ?
2. If i get a denial(rejection) for my extension , would it hamper my chances of coming to US in the future, since i hold a 10 yr multiple entry B1visa. I have read contradictory views so wanted to confirm. Also would applying for an extension create a black mark against my name the next time I apply for an L1 visa or H1B visa.
3. If the status is pending i intend to leave by the planned date(28th Aug). In this case would there be any issues with not having heeded the response(approval/denial) from uscis.
Any response would be much appreciated..

 

[Triple Citizen]

A1: Not very likely
A2: Possibly.
A3: If you leave before a decision is made and after the I-94 has expired, you will still be considered an overstayer if the I-539 is eventually denied.

1. What are the chances of getting a response from uscis before 28th Aug ?
2. If i get a denial(rejection) for my extension , would it hamper my chances of coming to US in the future, since i hold a 10 yr multiple entry B1visa. I have read contradictory views so wanted to confirm. Also would applying for an extension create a black mark against my name the next time I apply for an L1 visa or H1B visa.
3. If the status is pending i intend to leave by the planned date(28th Aug). In this case would there be any issues with not having heeded the response(approval/denial) from uscis.