Hello

Details

1. H1B and I94 expired on May 31, 2011
2. Applied extension I129
, Notice date May 17, 2011 at VSC.
3.Still in initial review, under security check.
5. Current project is ended and joining new project from 10/10/2011.
6. Employer is same.
7. Not yet receive any RFE or denial.

Que:
1. Is there any time limit for usics to complete security check.
2. Can I stay and work in US after completion of 240 days from I 94 expire date with my existing employer.
3. Is premium processing going to help.
4. What happen in case of h1 transfer to another company, Is H1B transfer help me staying after 240 days.
5.Please suggest me best options which I can do to stay and work after 240 days.