Can I still use my Non-B multiple re-entry visa if my work permit is revoked?

Visa valid as long as the date.

Extension which have is dependent on job and work permit.

You are meant to cancel them.

If your employer does or has cancelled them then you are on overstay.

You are meant to have paperwork from your employer stating when you finished work to cancel WP and extension.

I am doubtful you have a Non-B visa at all and it's far more likely you have a year extension of stay with a re-entry permit. CHECK your stamp, if it says 'extension of stay permitted until' and has a date you are on an extension not a visa

No, once your work permit is cancelled you no longer meet the requirements to have that extension anymore and you need to take termination paperwork to the immigration office, cancel your extension and then leave the country (you can get a 7 day 'get out of thailand' stamp that gives you a week to get out)

You'd have to come back on a new visa or a free stamp entry and go from there, but you can't stay on an extension once you fail to meet the requirements that extension was issued for