Dual use items for personal and business stuff can be linked quickly to give us an accurate cash flow accounting at a high level without investing a ton of time banging stuff into a customized spreadsheet.

Teacher comes in, takes a seat, and bangs both knees pretty hard - not happy at all.

Buy "buying" equity, it would in theory make it easier to refinance into a conventional mortgage (i.e. 70 - 80% LTV, 4.5% interest fixed for 30 years).

That's a tremendous return on a 15 year note... and while $540 a property won't seem like much, in 15 years that will be $5,000 a year on that property (assuming rents don't rise)... additionally, if you're only in each property $2,000... you could in theory buy 43 properties with the $86,000 out of your primary residence... that's $23,200 a year... not bad... in 15 years when those 43 properties are paid off, you'd be looking at $2M a year.Now, lots of assumptions... that's a lot of mortgages to have, even small banks may get nervous at some point... and that interest rate won't be available for ever... finding 43 2% homes wouldn't be easy (I'm surprised finding 1 is easy honestly)... getting a 2 for 1 bank for your buck on your rehabs (buying under market would help too!)

In sounds good in theory but most agents get 2.5% - 3%

Well there goes the theory that in order to be a moderator your name has to begin with the Letter "J".

Minimal utilities, low (in theory) expenses, no toilets.

I agree with everything you're saying in theory and we're certainly still toying with a house hack idea if the right property presents itself.

That's the theory anyway as I mentioned I'm not at a large scale to pressure test this setup.

Also, there is always the bigger fool theory.