What I take some issue with is the techniques that guru's use to up sell and so on .. and they do nothing to qualify if the person paying them if the program does not work they are now into debt to the eyeballs and so on but then again who are we to say at some point.. think of  Hewlet and Packard they went into 15k worth of debt to start HP in late 40s or early 50s and that was a ton of money then :)

The main factor is will rents cover the debt liability and can you sustain 3-4 months of no income to cover the debt? 

We have a ongoing list of each along with their fees and what state they are licensed to collect debt in.

I think he is over leveraged to a 90% debt ratio.

typically (as you probably know) you buy something distressed, with either cash or hard money, you fix it up, and then you refinance into long term debt. 

Due to my W2 employment I cant have any bad/negative personal debt.

Wanted to both reduce our debt load and also take profits off the table. 

It sounds like you’re setting up for a solid multifam portfolio—between you and your dad, the combined entitlements give you a lot of flexibility.

Take a look at the overall picture, i.e. credit score, debts etc.. to make a decision.

Sounds like their combined income likely beats your other tenants.Your gut is probably your best bet and you need to go with it.