Maybe consider bringing one on as a co-agent if they are willing to and if you legitimately think that you have the time it takes to dedicate to drafting and completing the forms/contracts, working the transaction through escrow, coordinating inspections, etc.

They suggested having a co-signer on the mortgage.Any tips?

As a beginner, you can learn a lot from your uncle with a few rentals in another state or a co-worker that's on their second house hack.

Would you file an ethics complaint against a co-member of your association if he/she "breached" a contract while acting as a principal and having properly disclosed that and licensee status in the agreement?

Neither land contracts nor a regular mortgage should affect a co-signer's ratios, if they are private loans.

What's replacing are larger medical complexes with multispecialties, all within an ACO or IPA (accountable care  organization / indepedent practice association).  

I connected with a co-worker who referred me to a contractor. 

This needs to be very clear upfront and communicated throughout, otherwise missed rent/electric payments could become a habit (having a co-signer helps with this too). 

This was when I had 1 STR and I have learnt the hard way that self managing or placing someone local - ( cleaner/handy man or even a co-host) is the way forward. 

An option I can think of is getting a co-borrower to sign on the mortgage with you.