My opinion on this would be to add it if you want it for yourself while you still live there, otherwise I wouldn't bother.

After reviewing the cost to rehab and the area of town, I decided to Wholesale for a quick profit.Sold it on a Real Estate Contract (Owner Financing) with $100k down, the balance is financed at 10% for 13 months, then the loan is called.

I would like to put "friendly" liens on them as a barrier to fraudulent transfers, which are apparently on the rise. 

Well....should you invest in a city where the people elected a woman with foreclosures, liens, judgements, garnishments, ethical violations from the state ethics board,  misused a city credit card, went three years arrears on her federal taxes all while yelling for other people to pay "  their fair share, " left skeletonized dead bodies hanging over Canal St for months on end covered only by a tarp until the wind blew it off to reveal to our horror her blatant disrespect for human dignity?

This is what causes people to not call ever and to have friends fix stuff the wrong way.If they want something checked out and then it turns out to be fine, maybe then a service call would be warranted, but not every time especially when they are service issues that are on you.$250 a call for someone is insane.

Can I just deny him on the sex offender account alone?

Quote from @Chris Doakes: So do you have a recommendation on another PM in the area? 

A lot of development is happening and she is not sure if she should hold on to it or try and sell it.

I had this happen earlier this year since I was not on the agreement, but found the buyer the deal through a wholesaler.

You have to ask lots of questions and make sure you have some level of understanding about cost segregation and not relying 100% on someone else, even though that is what you are paying them for.