Or perhaps a judgement against the free-riding co-owner for delinquent fees?

I can say when roles are reversed and I am the customer, nothing makes me more frustrated than a company not getting back to me in a timely fashion (or sometimes at all).

Fortunately my niece is actively investing in rentals so I plan to tag along for the ride.

It's possible to re-zone a property but it is an extended affair that could take at least 6 months, plan on 12 (figure several postponed city council hearings, hoops to jump through, etc. and you get the idea), and I would not count on that as part of the deal at all - that should be "gravy", not something you count on for the deal to work at all.The best thing I think you can do is ride by the property, maybe talk to neighbors in the area too, and see if you can figure out why it's zoned Light Industrial.

This allows me to scale more easily but in a pretty leveraged fashion.

Has anyone in this kind of climate charged their tenants in this fashion?

It also appears that there is a circuit for an electrical stove that perhaps could be used in some other fashion.

Credit card promo rates are great to finance anything for short term but will come back to bite you if you let it ride for too long.

Unfortunately, many managers do not operate in the same fashion that you would.  

Now that the market has recovered, I'm seriously considering 1031 exchanging those Antelope Valley properties to more expensive and stable markets closer to me so I don't need to ride the roller coaster back down, though I'll be fine either way.