With enough tenacity and grit anyone can improve and over time effort and consistency pay off.  

Then you could place a $1M umbrella at a lower cost and still improve your coverage.

I will be 90 years old before it needs major improvement.

The tenants are responsible for reporting issues to you so you have an opportunity to take care of the problem, improve their living situation, and protect your investment. 

Keep the rest for improvements and vacancies.

Another reason they are interested in continuing is the property's multiple exit strategies and high appreciation potential because of planned infrastructure improvements.

I am really interested in Wholesaling and I do hope to improve a lot and get better and better.

None of them are expensive and if you did all of them I'm willing to bet you'd see a big improvement.  

We are currently in discussions with contractors about improvements needed to her home (she has done little work on it over the past thirty years) prior to renting and are feeling totally overwhelmed.

However, within the seasoning period that may want to value the property as "purchase price + cost of improvements".