So in the mean time, I been keeping busy with working on my own properties and a few small landscape and PM accounts. 

Should I sell or keep it as rental?

If he were employed by a company, you might be able to get wage garnishment, but that will be harder if he is an independent contractor.3) If you have a judgement, yes, but keep in mind the collection agencies usually keep 50% of collections.

If I can be proven wrong I would LOVE that, becuase it means that there are a crap ton of creative ways of helping people with 2-3% mortgages achieve all sorts of things while keeping their loan that they don't think they can...

I personally use Avail for PM & Stessa for accounting/book keeping.

Keep in mind to be competitive in most markets today with HML when your up against Lima one or Kiavi a default is generally not going to make you money its going to cost you money.

@Timothy Eaton I have created an initial application that has basic information on it like name of all tenants applying, address, make and model of any vehicles, previous landlords, personal references, and I ask what types of debt they currently have and any pets.

What is your opinion of this approach and is there anything I should keep in mind before moving forward?

You're likely to get the best terms at a local or regional bank that keeps their paper and services their debt themselves.  

If you can make a profit, I'd keep it.Can you qualify for both mortgages at the same time?