This is something I'm concerned about too.

Other than checking out that the girlfriend doesn’t have any red flags on her report, what is your real concern?

One item you mentioned that is concerning is you said you did 200-300 letters to handout and you gained one contact but you lost track of.

A few specific concerns would be the length of the lease, the credit strength of whoever signs it, the strength of the tenant's business, and any rehab or Tenant Improvements (TI) discussed in the lease. 

Hit a snag in my investment goals :Scenario ;I have 85k Saved to invest I made 6 figures in 2018 Have 60k in equity in my existing rental property in Nassau county New York Good Credit BUT ....I lost my job last month and I’m concerned lenders will give me a hard time for not being employed, although I do have a small business that is brining me at least $3000 a month in profit.

As far as MF is concerned I wish it were so; but I have yet to see any uptick in availability of MF in any market close to my area.

I'm in clear danger of the seller's patience running out.   

I've been concerned the manager is going to significantly increase the rent at some point, at which point I'll have to figure out whether to stay or go, although it's likely that the new amount would still be less than if they had raised the rent a little bit every year. 

I live and invest in Johnson County, it's basically South Fort Worth as far as competition is concerned (high competition).  

The concern we had is he did not pay a security deposit when he moved in 3 yrs prior.