H1B Transfer

[ZeusChicago]

Planning to change jobs. My situation - Current H1B is valid till July first week. Company already applied for extension..but might take more than 3 months to get the approval.

Have a job offer from another company (havent accepted the offer yet)
Questions
1. What if my H1B transfer from new company doesnt come through before July first week and current employer withdraws the extension? Will the transfer be invalid
2. Can new employer apply for a premium transfer? (is there something like that?) how long does the premium processing take?

Thanks