We've got over a dozen of properties loaned with conventional mortgages and at this point it's getting more difficult to get advantageous rates for additional properties.

However, I am not trying to take advantage of my business partner either. 

How do you think you might be able to take advantage of this new ADU law? 

This pretty much leaves me looking for run down properties; I'm not sure I'd want to be responsible for fixing up my very first property (and primary home).That leaves me wondering if it's possible to take advantage of economies of scale.

I am in the process of refinancing so that I can take advantage of lower rates, eliminate PMI, and get a lower payment to increase cashflow. 

A lot of investors can create passive income by being out-of-state although it does require more networking and thorough vetting of the team you work with.Getting yourself connected to a local realtor who is familiar with the investing market will then hopefully allow you to connect to boots-on-the-ground teams and property management companies who can protect your asset(s) and your interest.Right now, the mid-west markets are doing really well - you can stretch your dollar further as property is typically cheaper but still allows you to hit a great ROI with the right homes in the right areas (this is where your connections come in).Social media, like Facebook, BP, and Instagram will give you insight in narrowing down what markets may interest you most - some of these can be hard to get into so utilizing social media to your advantage to grab off-market properties in appreciating neighborhoods will be key.Best of luck to you!

There are advantages of a cash-out refi (mainly interest rate that is both lower and fixed), but a refi will have more closing costs.

And, if typical loan terms are typically far higher for these slightly bigger buildings, are there other financial advantages to buying, say, a 6-unit vs a 3 or 4 unit that would outweigh the disadvantages? 

Why not take advantage of the development going on and use the value increase to exit the property to reinvest capital in new investment opportunities. 

Many investors don’t get a license since they believe they may be held to a ‘higher’ standard or could be accused of ‘taking advantage’ of un-represented sellers – but all these concerns can be handled by proper disclosures.