So if you go the route of a PM make sure you know the contract, can you get out of it and what are the penalties, what if you sell, if there are repairs over a certain amount, do they contact you first, etc. 

If they don't they will have to pay that rent or you can seek a judgement against them. 

My main considerations are 1) this is a good tenant who always pays on time and never complains and 2) the increased rent at this point, though getting to be significant, would still take 4-5 years to cover the cost of renovation.Tangentially related question: when would you pay cash to renovate versus seek a renovation loan?

A sign of good faith, this amount consequently allows for additional time to seek financing.

Its in a mid-range property - a 4 BR duplex that we will seek about $2-$2.2k rent, hopefully a B+ property in a B market.  

Some states are notorious than others and have penalties. 

If you are going to do this yourself and not a manager I would highly recommend you seek a local real estate attorney. 

We can usually quote and generate a pre-qual letter within an hour of the request.Let me know if you're still in need or if you found what you were seeking!

The seller carry is on a ten year term with a pre-payment penalty for any payoff in the first three years - a balloon payment anytime after three years incurs no penalty.

You can’t do any work on it, run the property management or stay there yourself or you will be considered to have withdrawn 100% of  the funds and you will owe penalties and taxes.