Sadly i only know of one court case where the person with a w2 was able to qualify.

If the person who emailed you has the authority to release the agreement, then I'd say the email is sufficient 

The Solo 401K would allow a loan, and those funds may be used to invest in your personal name.

From my understanding, if its passive income, just a room-by-room rental, it would go on your schedule E just like any other rental. if its active, like a short term rental situation or mid-term, something like an airbnb or bed and breakfast where you're actively including extras, it would be filed on a schedule C. disclaimer, im not a tax person, so double check this with your tax pro. when you go to qualify for your next purchase, whether that's for primary or inv., using a full-doc loan... if its schedule C, you would need to do a 2 year average of this income in order to use it. its looked at as a business, and self employment income. if its schedule E, theoretically you could use the schedule E income calculations just like any other rental even after the first filing.

If you're looking to run numbers and get an idea of what this investment looks like I'd be happy to sit down with you and get it done via Zoom or in-person. 

Personally, I'd recommend looking into areas like East Rock and Westville as they're considered "safer", though most multi's seem to be in-between the two areas.

We run the credit report and background of the personal guarantor.

I am interested in buying a condo or house near a New England ski resort, with the plan to rent it most of the time and while keeping a few weekends open each year for personal use. 

If you have self employment or gig jobs you need 2022 and 2023 IRS taxes filed and all the pages/1099/w-2/LLC/Corp/personal and 2024 income.

What would help is if you had a partner or family member with better credit who would be willing to give a personal guarantee alongside you.