So the Property manager is making 60%+ of what you make as the landlord (speaking in straight cash flow terms).

In Florida most of our compliments are of the outdoor amenities (pool, heated pool, spa) etc.We have a discount on Helix mattresses we extend to our clients and have been getting quite a few compliments on the mattresses. 

If they are difficult, the current landlord may not give you a straight answer because they want them to find a place and move out.

Finding some sort of value-add aspect or buying at a discount means you either create or walk into equity, which protects you.

when the OP said the bank is WILLING to take 91k to me that means or infers a default situation and a discount..

Here are the pros as i see it: easy (no purchase necessary, you know the property), likely prop 13 property tax discount, possibly below current rate loan.  

dont over think this its not that complicated. important issues are.1. cost of capital2. knowing what a deal is or is not.3. good reno crew or contractor  4. good agent that will tell you straight what its worth when done and what level you should rehab to.5. a market that is actually moving napkin math works  trying to drill down to decimal points does not.

The reality is that with the super low inventory we have sellers don't have a reason to give you a 50% discount, so your numbers get squeezed and you will end up leaving cash in the deal.

I very much wish you well in your journey, but I would hate to see you jump straight to the NFL. 

It's very easy to keep it all straight.