I have gotten a seller's credit for my 3 existing units but to be conservative, I will assume I am paying full closing costs here.At the moment, I have ~$25k in a HYSA and expect to save another $10k from my W-2 before I start putting offers in.

Recommend you don't make an offer. 

If they are relatively the same but offer a front desk etc maybe they are superior. 

So he bought up several owner financed properties that offered 0% down, and he cash flowed. 

I haven't read this page to see what's offered as conservation incentives, and then compared that against your local market prices for "junk" land.

For further context, we are trying to have him be the name on the loan because he would be able to utilize his first time home buyer loan to take advantage of the lowered offered interest rate.

The rate the manufacturer offers is 4.8% which is why I am going through them.

Your maximum allowable offer. 

Purchasing a “distressed” property and “repositioning” it requires significant capital for improvements, build outs, holding costs, maintenance.In looking for that “needle in a haystack” slam dunk great deal you’re competing with very knowledgable, greatly experienced investors with the cash to make no contingency offers and close in a few days.  

Provided I can establish a solid investment plan tailored to their financial needs/comforts such as debt ratios and income, they would be more than happy to offer me some financial control.Additionally, If I wanted to, for the sake of building my own personal wealth, I admittedly have the luxury of taking a loan from my parents.