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.

This indicates a demand for smaller, more affordable housing suitable for singles or young couples, which are typically quicker to flip due to higher demand from first-time homebuyers or renters.

Just to add on to my last comment...Ask the contractor to redo the estimate with more detail and if he/she balks or stalls then find another contractor...that is a bad indicator for the $37K job he/she has ahead of them!

Credit scores are an important indicator of tenant worthiness, but I have also heard that $60k a year (in most markets) is the magic number/ minimum income number for most good tenants.

However it’s a strong indication that it isn’t a good deal.

Reductions in the price of long-standing homes may be an indication of motivated sellers, providing a chance for a negotiation, particularly if Zillow estimates are lower.

In a similar fashion, if you can imagine how much landscaping and underground infrastructure is in a golf course as compared to the clubhouse, that will give an indication of why an extremely high percentage of the property's value is allocated to the land improvements.

All factors that could indicate the economy is cooling down are NOT, in fact, indicating that the economy is cooling down.Can you afford the property at the current rates you will lock in indefinitely or would the payment eventually crush you? 

By the way I recently gave notice to tenants that lied on their application which indicated no perspective tenants smoked.  

I do, but I do show them the comps and indicate that since they have been a superior tenant, I am only increasing the rent a little, still keeping them under market value.