Most Standard companies do not like a Renovation where part of the structure is occupied.   

He never showed up this and after trying to reschedule several times I found a new company. 

I would prefer the risk of a renovation to upgrade a building as opposed to location risk with a high risk tenant pool. 

A partner of mine who worked for a RE development and research company says they regularly used Yimby data for studies. 

You don't need to...markups in retail are pretty uniform throughout the supply chain, and for public companies like Walmart, you can look at their quarterly filings to determine exactly what their margins are.With contractors, you don't have this same level of transparency, so if you want to ensure that you're getting reasonable prices, you need to do some additional investigation...

One of the mortgage companies has approved me, subject of course to an appraisal.

If the AC is not working you will need an HVAC company to come out and tell if it's fixable or needs to be replaced.To be honest, everything you are saying indicates you are going to create a money pit for yourself.

I guess the other option is to use a property mgmt company to find a tenant for you, but I just thought it would be interesting if there's a site where the landlord can peruse a list of quality tenants and reach out to them directly! 

Do we write a check and have the Title company hold it until work is complete?

*Insurance company came by, did an inspection and stated the property was vacant.