When you eventually sell, your potential market is investors - this can mean many things, depending on the state of the market when you sell. 

Here is a link to the Las Vegas short-term rental page: https://tinyurl.com/2fcsjj32Whether you can offer a short-term rental out of a condo or apartment depends on the individual property.

I understand that everyone has unique goals, and responses will vary depending on those objectives.

My recommendation is that you make it a tenant responsibility in the written lease, then send reminders every 3-6 months, depending on the schedule.

That highly depends on your pay structure.

. $25k for helical piers sounds a little steep, but it's been a few years since I saw a quote for that, and of course it depends on how many you need.

You can also just buy it as an investment property with 25% down if you have the capital to put that much down on a 1-1.3 million 4plex depending on the area.

I have 2 good friend RE agents available if need be but I think this might be a "transfer of loan deal" just depends.

It really depends what your goals with REI are.

Maybe he does file a nuisance mechanics lien (whether he can and precise procedures) will be dependent on local law.