Maybe a photo of the drivers lisence?

Interesting combination you have here - driver and investor.

The seller wants to close fast, within two weeks, but would like 30 days after closing to move everything out.So we would close at the end of October, but full possession would be given, say, December 1st.Can I simply rewrite the Possession clause in my Purchase Agreement to say "Possession of the property and occupancy (tenants excepted), with all keys and garage door openers, will be delivered to the Buyer 30 days after title transfers. 

Your education has also prepared you to analyze cycles and this point in the market is not an easy entry for passive investors not willing to be a small part of a much larger endeavor.In your case I'd be looking to real estate more as a tax hedge that will build substantial cash flow over time while delivering substantial depreciation and tax benefits from day one. 

My mother lived until the age of 96 and never had a driver's license.

Otherwise, a 30 day written notice of non-renewal delivered in the correct way should be sufficient to have the right to take back the property.

I already asked the bank if it could be delivered vacant but from how they responded I think they want to avoid that headache.

Have your attorney make it a condition of the contract that the seller deliver one unit empty for you to be able to occupy.

The actual rehab cost was $125,000, and we have delivered the property on time.

I've talked to the current PM, and while he's usually leery about managing non-conforming properties, he said the fact that the postal service didn't raise a red flag and is delivering to all four units is good enough for him that there'll be no issues with the county.