I know that in my market in Greensboro, NC, sometimes the difference between attracting quality tenants and having months of vacancy/multiple evictions is only a matter of a few streets over.

The purpose of the Multi-Family Residential district, also known as the R3 district, is to provide space for multiple family residential development commonly found in an urban environment.

So let's take your $50K and multiple it by 12.5. 

I’ve bought multiple houses with 20k all in, but 10k is going to be difficult.

I'm not familiar with all of New Jersey, so I was soliciting perspective from the BP community that may know of specific areas with the general attributes, which in hindsight were fairly vague. 

Things are perhaps different on your side of the 49th, but why would borrowing money to "invest" in private loans be any different (from a tax perspective) than borrowing to "invest" in any other {legal} vehicle (stocks, bonds, real estate)?

Another thing I'll mention is the landlord as broken his own lease multiple times by entering our house without permission while nobody was present and often walks in unannounced.Appreciate any thoughts

Maybe others will have a different perspective but if I’m going to have to use owner financing for a random lot in Tulsa, where or how will I come up with the money to build a house?

I have been told by multiple tenants that they chose my house over another because they wanted to deal with me.  

You will have to go through probate with an attorney to transfer title, unless property is in a trust, or if property is appraised under 150K, at the date of death, you can do a terms of succession, which is usually a few months instead of a whole probate process and if there are multiple heirs it gets tricky.