Also I can't say for sure from the pictures, but it is unlikely those 2x4s are sufficient, even if temporary.

Ensure you have a solid plan for renting the property and generating sufficient income to cover the costs of the HELOC and any other expenses associated with owning and managing the property.Furthermore, exploring alternative financing options, such as personal loans, partnerships, or even seeking out potential investors, might be worth considering.

The best ways to verify financials is to look over tax returns,  water usage data, etc. you’ll want to know if the laundromat is QO, DC/token, card system or a combination of all of these.

I make sure the street and the houses on that street, along with the streets around it are sufficient to produce a good resale value.

Is that sufficient?

If you have a relationship with a good attorney who can guide you through the process and sufficient excess operating capital, including reserves, maybe you could start in the business by financing someone else's deals.

During college, I lived in student housing that was covered via grants/scholarships, but in grad school I rented a privately-owned property that I had to pay for via a combination of my own money and student loan debt.I'd say that in most circumstances, if a college kid is blowing through 3k/month, they're living a much too lavish lifestyle (and probably don't have sufficient scholarships/grants).

My understanding is that for a space to be considered an ADU, it must be self-sufficient and have a kitchen.

Contrary to the comment above, insurance (while being a great first defense) is not sufficient in an of itself for all liabilities.

The gift is just one small token of appreciation.