tier 2 (shortage occupation) to tier 1 (exceptional promise) and cooling period

[pixgyp5]

Hi all,
My tier 2 (shortage occupation) sponsored visa is coming to an end at the end of this month, and I will hopefully get another offer soon.

- Is there a grace period of 28 days to find a new job before I am deported?
-I also have to leave the country in mid April (for just a weekend), and it is after the end of my visa expiration. Is there any way to be able to go without activating the cooling period? Is there anyway a potential employer can indicate that I am coming back to a job here in the UK?
-If I don't get an offer for a new sponsored visa, I am qualified to apply for tier 1 (exceptional promise). If I have put in my application for endorsement for the Arts Council, am I allowed to leave the country and come back without activating the cooling period?

Thanks for your help!