I could continue to build on credit but am uncomfortable with tying up such a high percent of my capital in a single investment.

How is your credit history?

Assuming great credit even though I thought that the whole point of a DSCR was that the purchaser credit did not matter and it was all about the ratio of revenue to loan.

Now, take that to 80% and drop the credit score 50 points and the rate increases by quite a bit, but generally, you're looking at a higher rate for non-QM. 

A year of rent sounds great on the surface but I’m wondering why they wouldn’t just pursue a normal year long rental…maybe they’ve been bad renters or have bad credit or low income.

DTI and Credit scores are excellent and the property has been owned for more than one year.I realize that there is a "Find a Lender" function on this website, but I really don't want to be spammed with marketing emails. 

We manage 37 doors with that costs us a few dollars per door per month with no surcharge for ACH payments and we get next business day credit for those.  

Confused because DSCR by nature looks at the income the property is generating and not your personal income or credit I believe. 

Typically what is known is done at closing but trued-up later.If your PSA specifies any credits for non-ready units, that will offset the other costs.

They definitely cannot run your GFs credit without her permission.