H1b pending cap gap. OPT expired expecting Lay off

[Dee8590]

My OPT has expired 15th may .h1b picked up in lottery but still pending. I am currently on cap gap but expecting a Lay off anytime. Employer might withdraw petition

1. Can I apply for any other job and will it be counted cap exempt

2. How many days of grace period of do I have before I have to leave the country. My program ended in March 2016  I took 60 days grace period and OPT started May 16th 2016. I am non stem so no OPT extension.

3. If I apply for a new program now will I have to withdraw my I20 from current university or can I countinue the I20 till my employer lays me off and withdraws my petition.I would like to wait till my employer withdraws my petition before getting a new I20 in the hope that my petition will be approved soon.