The m2m tenant presumably has lived there for MORE than 12 months, so based on AB1482 "no-fault eviction" legislation, you cannot simply give notice to vacate.

What happens to original security deposit from original 12mo lease?

For example, you might pay them $2k now for the right to buy the property no sooner than 12 months from now and no later than 24 months from now for $100k.

Hopefully you have a lease that you can point to that spells out things like "quiet enjoyment" and no unauthorized persons living at the property for more than 2 weeks, for example.

Otherwise, you are just gambling that the bank will not call the loan if/when they discover you have left the property (which probably states it will be owner occupied in your loan, if it's a primary) and are no longer making payments. 

I hear LLC, no LLCs but umbrella policies and keep pulling out equity to help with asset protection.  

We’ve been good tenants paying on time for the entirety of our stay here.The property owners are brother & sister (and I believe a third sibling), but they’re never really on top of things, and no property management.

There's just really no one size fits all and a lot of it is trial and error.

But usually wholesalers are preying on the desperate - the ones who had a loved one die and can no longer afford the house, or can no longer take care of the house, or who are behind on their mortgage and are about to go into foreclosure, etc.  

With the cash flow play you need to buy low, negotiate hard on price, expect no appreciation and get a very healthy cash flow, nothing marginal,  And expect when you sell to make little to no appreciation, then any gains are icing on the cake.