That's probably too much to unpack in one thread.

You have no more at risk than you do in your own home (where you probably have more equity.) or your own car (where you probably have more risk.) and we won’t talk about if you have a pool or a dog. 

Unless you have their contact info and are comfortable reaching out, Honestly handing them off to the local police station is probably your best bet.take pictures, and record any communications with the authorities to cover your butt.

When you are first starting out, you should probably buffer an extra 20% on top of your renovation budget to cover incidentals while you are learning the true cost of flipping.When you do all these things (conservative estimate of ARV, additional 20% estimate on construction costs, using a conservative 0.7 multiplier in your estimate), you are unlikely to lose on your first flip (but it will be harder to find your first flip).  

Probably the LLC is irrelevant (a disregarded entity) because it sounds like you've got spouses residing in a community property state?

@Mickael Castillo It's worth a try, but IME investors like that will probably blow you off.

7% is probably good for projections, but I would ask whatever bank you're planning to go with where they're at and factor in an extra 0.25% to be safe.

It is sad but he needs some help, probably supported housing.

I'm thinking I should probably let it go to someone that knows the game little better! 

The Gator II group ($5k) and then a Sub"something" (I can't remember) and that's probably the more expensive one.