However, while the results of your big lift may be lower operating and maintenance costs, if the local market will not support sufficiently high rents to provide a timely pay-back, you have over improved.   

Quantities are fine as this will help to get to "apples to apples" comparison when looking at cost and amount of work.

FHA also has a rule called “Net Self Sufficiency” meaning the total mortgage payment must be less than the total rental income on the property.

Once you hold that TIC for a sufficient period of time,  you could sell it to them, and do a 1031 on that sale.

Since he is short on time he is going this route for a few months until he has sufficient time to look around.

However, your landlord is likely notifying you of  the complaint because there are sufficient complaints from her other tenants to warrant letting you know; concerned that other good, quiet tenants may leave if the issue is not resolved; and covering herself in case there is an actual drug issue. 

What I should have done as you rightfully point out is to seek sufficient time to be able to get all necessary bids. 

And I was surprised to learn a select few companies have prioritized quality over quantity.

I tend to stay on the low rental side because I prefer quality over quantity. 

The fact of you mailing Certified Mail with the RECEIPT is sufficient LEGAL Proof of delivery to the Tenant, and will standup in any JP District in Texas.