70/30 investor fund structure to make this deal go.

Quite the opposite - I invest my personal money as just one more member, in each investment we end up doing as a club. 

I used a personal line of credit of $8k to invest.

Quote from @Jeffrey Duck: I see no reason to pay an attorney for this, but it's your dime.The current lease was between you and Person B.

Leverage Other People’s Money (OPM) & SyndicationsI built most of my portfolio through syndications because I realized I didn’t have to fund every deal myself.

You have to have confidence and the Sponsor needs to build a relationship with you if he wants to be sure you have some insights into the risks of the types of deals you would be funding. 

Underestimate the costs and come up short needing the funds?

Many Gen Z buyers, however, are still in the process of securing their down payment funds or comparing loan options when they start making offers, putting them at a significant disadvantage.Looking AheadDespite these challenges, Gen Z homeownership demand remains strong.

Is it their credit score, their track record with loans, or the investment they’re trying to fund?

If you’re not willing to do this, then you may be best off investing in some kind of real estate fund concept.