In my opinion, the agent is the critical piece.

In my area, that includes the following:Race, Color, Religion, Sex, Familial Status, National Origin, Disability, Military Status, Sexual Orientation, Age, Creed, Marital Status, Gender Identity, Source of Income, Immigration and Citizenship StatusBeing 19 y/o, the tenant is feels that this is unfair treatment based on age.

@Patrick McCracken Many local lenders will also allow you to use line of credit capital as your down payment source FYI. 

Source of down payment funds, if applicable: own funds, secured borrowed funds (HELOC).Income Source: Salaried FTE W2 until 7/1/21, 1099 independent contractor (healthcare consulting for 2 years)Gross monthly income (optional): $6KMonthly debt obligations appearing on credit report, plus (if applicable) personal rent and alimony/child support/etc: $1,400FICO: 696Credit issues: One late payment on a card recently, currently owe $4,700 in cards.  

If you need to push a less critical date 1-2 days and you still have contingencies in place normally an email will suffice, assuming all party’s are cooperative. 

While this could have been kept in the portfolio with sourcing better management, there were other properties that were owned that the capital would be better used on for us.

Another wrinkle is that I was debating whether it'd be a good idea to get a HELOC on our house as another source of capital, but would that also be factored into my DTI?

Tenants are often the best source of information.

If the note is already actively for sale through one of the various sources, yes.

Reading BP posts has helped me understand concepts in the past, but now I am in a critical position and in need of some advice from the best.