T-2 Employer Sponsored Visa - Wish to resign

[9elizabeth]

Hello all,
I am posting this enquiry of the behalf of my friend:
I entered in UK on 20/8/2019 on T 1 Employer Sponsored work permit (by NHS). Due to my personal issues, I wish to resign from my current job. My visa is valid till 30/10/2020. I would like to go back to India spend some time there (a few months) and sort out the issues and then would like to search a new job with other employer and come back to uk again.
It would be helpful if somebody could answer me the following questions:
1) As soon as I resign, will my current visa be invalid? Is there any time period when I have to leave UK before I am considered as overstayer)
2) If the answer to the above question is NO, and If I find other job while still in UK can I apply for a new visa within from UK?
3) if the new visa is applied from abroad, is there any cooling off period before I could apply for a new visa?
4) when I get a new visa and come back to UK again, will my current time spent in UK be counted towards the 5 year of period for calculating the ILR or the new visa will re-set the 5 year clock?

Looking forward to hear from you.
Best regards,

[CR001]

1. No and no.

2. Yes.

3. Yes, 12 months.

4. No it resets to zero.