As you mentioned, your dollar goes much further in Louisville than it does in California, and because of that very reason I've been searching the Louisville market for investment opportunities.

Not to mention your husband will still be using it as his primary residence until he deploys which is another exceptable reason to stop using it as your primary residence. 

Thanks for the mention @Yonah Weiss!

There will definitely be new laws, but so far it looks like they're going to make it slightly easier in areas where it is not currently (rezoning as mentioned), they may even promote the process in some way, and there may actually be a housing regulatory overhaul in general that will affect all rentals (long and short-term (though that is quite a ways off)).As with long-term rentals, there are plenty of "slumlords" on the Airbnb side.

Not to mention good ol' San Diego just doesn't cut the mustard. 

Next you go buy a multi-family in one of the areas you mentioned (Assuming average $200K/unit and 4 units, which seems on the light side, $800K purchase price, $160K downpayment) which would leave you with $160K in cash. - The problem I see here is that I highly doubt you would receive cash flow in this scenario.  

It is a fairly low income area. while the area is rough, its actually on the much nicer side of town, not that it really helps, as I mentioned I'm viewing the property this week and plan on doing some more thorough neighborhood recon.

As mentioned previously, all expenses directly related to a specific property to include mortgage interest and depreciation are taken on Schedule E for that property. 

If I can’t get out of it easily, it needs to cash flow more and get the higher end of coc return on the ranges mentioned above.

You didn't mention what you were looking to buy but If you are looking to buy a rental just make sure your numbers work if rent prices decrease.