I have a current Q1 visa which is due to expire in December. I plan to travel home in November, whilst I'm there is it possible to apply for an ESTA to travel & holiday in the USA for a few weeks and then return back?
Yes, you can return to the US on the Visa Waiver Program after having left your Q-1 program. Of course you may receive some additional questions from the CBP officer regarding why you have returned so soon.
You are required to reside outside the US for at least one year before you can return in Q-1 status. If you don't intend to return in this status, this is no problem. If you do intend to return in Q-1 status, your brief visit on the VWP will not count against this one year foreign residency requirement (8 CFR 214.2(q)(2)(ii))