I have a development and construction company and used unlicensed subs a lot of times when I know the quality of their work.With the 30k budget, it is doable for touch up and re-sand/paint projects without major changes (depends on sqft as well).

I know this doesn't help you get your money back but you can always report them to the MN Dept of Labor if they are unlicensed: https://www.dli.mn.gov/busines...For future reference what is nice about hiring someone with a license is that you can be eligible to use the recovery fund for an out of pocket loss.

Does he have mechanics lien rights even though he is unlicensed and not required to be licensed in the county?

Depends on your state I think as to if they can pay unlicense entities commission.Some people think LLC creates some anonimity and protection. 

If I try to get these title issues taken care of with the seller or negotiate the price with the seller, am I doing unlicensed brokering at this point since I no longer have rights to the contract?

Not only unlicensed but really inexperienced?

As long as your the owners of the properties then good to go.There is a ton of unlicensed activity around this business of reselling properties in other states IE starting an OOS marketing firm. 

Regarding $$ - a typical unlicensed, 5 BR home is going to net around 2-3K/month. 

Recent examples: someone self-managing their property hired an unlicensed contractor.

Each of these approaches have pros and cons, even the local guys struggle to have a perfect system.Rehab company- This is similar to a GC, I'd more so call this option using an unlicensed GC that has access to a lot of crews.