And what I am proposing to the lady that lives there who is 88 and has zero cash.

I think it interesting the lenders (mostly F/F) mandate insurance, but not earthquake insurance even when you are close to significant earthquake faults.It is my personal view that if a big enough earthquake hits that it causes significant damage to many homes that it would be declared a disaster and cheap loans and options are likely to be available.It really is a calculated gamble.I have a fairly large umbrella policy.  

Owner's policy is one time fee based on sale price covers you as long as you stay on title (owners title policy is higher).

Any tips for getting that owner finance deal or other outside the box thinking for zero down is appreciated.

There are plenty of insurance companies that will write a policy on these types of buildings.

My question is what ability we have to enforce certain “policies” such as requirement to maintain renter’s insurance(their leases don’t require it) prescribed method of payment (they currently deliver cash to the landlord’s local bank) or increasing their deposit (some are as low as $100, and one tenant has no deposit at all)?

Zero interest  2.

and subs should have no problem proving they have insurance and will add you to their policy this is standard Operating procedures. 

USAA and Amica do a great job of taking care of their policy holders and writing a proper scope of work / paying for quality work. 

It was about getting an insurance policy to protect you in case the bank calls a loan from the “due on sale” clause.