If an agent is involved your chances of having a meaningful conversation with the seller is limited. 

They come to realize  fractional ownership in a semi-active project with far less control is not as advantageous and eliminates the ability to build the more personal and meaningful relationships with lenders that comes with going through the more natural progression of growing a portfolio and business. 

When Portland did something similar, it sparked an ADU boom. 

There are too many unknown details here to give you much of a meaningful response, especially if SEC rules are in play here.

Best to always identify quantities and tasks to improve and then plug in some meaningful allowances for each if you can?

It'll keep you organized and help you maintain meaningful connections with your network.

As @Chris Seveney mentioned there is not really enough equity in house 3 to get a meaningful LOC. even if you were able to leverage enough to pay off House 2 the new rate you would be paying would be higher than the existing mortgage, so you would still be behind overall.Your ROI on those payoffs vs keeping money in index funds is not very good either.Lastly, remember that cash flow from rentals can seem good until it’s not.

I'm actively seeking to expand my network and build meaningful relationships with fellow investors and collaborators interested in growth and opportunity within real estate.

That's why lower tier neighborhood SF homes should only be purchased if there's a meaningful appreciation event around the corner.

It ended up sparking my love of real estate and I got my license the next year.