Urgent, need some information on visa

Hi all, apologies for the "urgent" in the title i just would like to have some light shed on my current situation i am in at the moment.

Here goes

This is my first year teaching in Thailand, i have been working at a school in Bangkok since last year march and my year contract will be ending on the 21st of February.  I work through an agent who i have a working permit with. Its period of validity is from (07/08/2018) until (31/03/2019) so it expires on the 31st of march (next month).
 

The problem is that i want to move away from bangkok and relocate to chiang mai, i will wait until my school contract is up and then i want to move immediately and tell my agent i am not resigning a new contract and that i wont be coming back.

So this is where i need help with:

1) Can a agent cancel your working permit for you? if they do how long do you have to leave thailand?

2) If my working permit is canceled via the agent and i do leave Thailand and obviously want to come back, what is the best way to do so? 

3) if my agent leaves my working permit to expire (31st march) do i still do the same procedure as above in terms of leaving and coming back?

4) is there anything else i should know about or be warned about?

5) Can i come back into thailand with a tourist visa after my WP/non B  is cancelled and have no issues?

6) what are the repurcussions of me not going and canceling my year extension? can is till do what i said in Q:5?

My overall plan is to move from bangkok shortly after my contract is finished then get settled as soon as possible in Chiang Mai (e.g finding a place to stay) . once that is done i will notify my agent to cancel my WP and then i do what i need to do to get back into thailand via a tourist visa.

Thank you in advance and please any help would be greatly appreciated. I am doing a leap of faith here and want to know if this would be alright.