The quality of the building, the real estate related demographics, quality of tenant, and lease structure are the most important things. 

One interesting find during the inspection of the "in law" suite was that no smoke detectors were installed in the furnished basement.That being said, this has me concerned about the potential quality of work that went into the rehab, and whether or not licensed contractors/personnel did the work?

Good luck finding a high quality agent who’s respected in their local market and also willing to give up half of their income to make your “deal” work.

Looking at current comps in the area for similar property type and quality positions this property to confidently be rented at $1450 per month.

Blink is an Amazon company and they have wireless, battery operated cameras with motion detection at a very high quality and relatively low cost. 

Could anybody suggest  an average ROI for typical medium/high quality new residential construction projects?

The price-per-unit measure would only work for properties in the same market and of the same quality.

The TK provide must be experienced, trustworthy, transparent in their communication and offers, and provide quality work at a fair price.

Everything must be primed with a good quality primer (Kilz or Zinsser) .

What about the Meter set for fresh water and a plumber to tie in the water connection to the house ( has to be pressure tested and signed off by City/County Inspector)Fire Hydrants need to be Chlorinated and tested for quality and leaks by Public works or Fire department depending on your local.