If so are you required to deliver it vacant or can you let the new owner deal with it?

I can PM you my lawyer (he is reasonable and honest, will not be promissing you things that he can not deliver), but there is not very much you can do.

And the 60 days to vacate start counting the day after you deliver the notice.in my case, I gave them 60 days notice to vacate on oct15th, which means that they pay rent from oct15-nov15 but they do not pay rent from nov 16-dec15th.

You must deliver the wet-ink note to the buyer along with copies of all the rest.

I’m always looking for ways to leverage the efforts of others who are awesome and/or can deliver great deals. 

Most systems don't deliver the efficiency that they claim because the test conditions are so different from installed conditions (SEER will be replaced with SEER2 that uses more realistic tests) and most systems are oversized.

We've already sold with seller financing and we're open to do it again for the right buyers if we sell some of the condos I mentioned above in Playa del Carmen by the time they're delivered in a few months.I hope this helps.

There are many turn-key providers who can provide you with great cash flow but you need to do your due diligence to ensure they can deliver.

And....for the future, write into your contract property to be delivered vacant if there are tenants in the property. 

It should be a very nice rental income for him over the long haul.You could also invest in syndicated apartment deals or mobile home parks, which could also deliver nice returns (so long as the operator knows what they are doing).Study up and get advice from as many experienced parties in the respected fields before making your run at it.