If your partner is a contractor and wants to keep busy, that could be a different story, but I at least consider looking at long term ownership plans and flipping as very different businesses and a lot to learn on both, so not sure I'd risk losing money and time dealing with flips. 

I probably wouldn’t mention your third point - it makes it sound like you expect them to hold this note forever and I’m not very certain, but I’m guessing there isn’t a huge market for $100k secondary notes.Have you considered asking them to finance 90-100% for a short period of time so you can rehab and refi at a higher valuation?

I have been considering getting into this space in San Diego.

If I were in your shoes, I’d consider a few key factors before diving in:1.Risk Tolerance:Ask yourself, “If the worst-case scenario happened and I lost this money, could I recover?”

No, none of my contractors were labeled/considered to be corporations.

If they’re facing a short-term financial hiccup and you feel they’re otherwise a reliable tenant, you might consider setting up a plan for them to catch up on what they owe.

I'm considering a major reno owner/occupied triplex in the Irish Channel, great walkability. 

I've considered putting it on Airbnb but haven't needed to yet. 

I consider these info be confidential and am reluctant to give all these info to them.

First thing to consider is what was the original foundation design and can it hold a second story to a home.