Wages here aren’t going up much, and may be going down in the hospitality industry especially, as the casinos continue in their union-busting and anti-worker efforts.

Do you have rent roll to prove that current slots there are actually paying and on time?

., one way you could free up some slots for traditional mortgages would be to take cash out of one or more properties and use that to payoff other properties so that they are free an clear. 

There's no harm in asking if they have an open slot, or if you can work around their other jobs - that's different.

You can use a multi-tool to cut a slot all the way around the room to increase the expansion joint, just make sure the slot is smaller than the baseboard (or add shoe/1/4 round molding). 

Do people want convenience to the beach, boardwalk and casinos?  

Just like in beating a casino, the law of large numbers should allow me to thrive.

As it is now, I only have one qualifying loan (filling one “slot”), but 15 commercial loans.

If that's the case for you, I would recommend getting it on either your or your wife's name (assuming you can qualify with with income from only one of you), so that you're only taking up one conventional loan "slot" since Fannie Mae/Freddie Mac only allow 10 per person. 

For example, if you're looking to attract tourists, consider properties near popular tourist destinations such as casinos, ski resorts, or water parks.