No downside to sending a letter but not worth paying an attorney here based on what you shared. 

People that work for you as a closer usually wouldn't have their name anywhere on the contract, etc, you are just paying them based upon your commission agreement with them.  

If they do they can pull data for you and market analytics.Of course there is a lot more that goes into it once you get that data but based on your question - that is how I wouldProceed.

Based on those Sedona STR income numbers for a $800k home, either the revenue numbers are wrong- and way low, or the property is not a good one as a STR.

Both are based on investing $10k and selling to get back your $10k.

Is there a certain cost per unit I can expect to pay based on the condition of the building? 

Basing maintenance/cap ex as a percentage of rent is not smart even though many rent calculators use percentage.

However, based on my revenue projections and factoring in a 25% commission for professional property management, it seems unlikely to generate significant cash flow unless they can significantly boost revenue.I'm open to working with a professional PM if they can guarantee decent cash flow.

I'm assuming I'll get a lower cap on that and my only way to add value is by increasing rents annually based on the provincial max amount allowed to increase rents?

Loan approval is mostly based on projected rental income, similar to commercial properties.Disadvantages - higher interest rates and can be a riskier investment.