A quad plex is still a residential property so easy to qualify for if your living in one unit for a couple of years.

I have been investing for 3 years and so far my cash flow percentage (out of total rental income) is around 1.5%. (cash flow from operations / total rental income) * 100% How much cash flow are you getting?

Typically, the 26% residential solar tax credit does not apply to investment property.

The 27.5 year depreciation schedule is for a residential property improvement as a whole.

Which if youve done flips , but not commerical multi before, you wont miss much,  however a 6 fam is a commerical code permit so there are slight variations between the residential code for essentially all trades which if you dont have a detailed plan and you dont double check every code before you do anything but rely on cheap labor to do your due diliegence for you, what could go wrong ? 

I've been a real estate agent since 2014 working in the residential side and have one investment property (bought rented and sold) under my belt. 

Is this typical to have 1 year leases and be treated more like a residential rental? 

Quote from @Chris Seveney: I agree in vacation / beach areas they are great but once you start getting into true residential neighborhoods I can see them being very problematicI think of course it depends so much on the neighborhood.

Based on your inputs, I think simplifying to a single management company and starting with a single holding company makes sense and then I will add additional holding companies as my portfolio grows.Nathan - on the $1m in equity per LLC portion, would you split properties up into separate holding companies based on type (e.g. residential, commercial office, commercial ag, etc.) or would you keep multiple property types in the same holding company as long as it's under $1m?

@Andrew Kubik look in to NARPM (National Association of Residential Property Managers) if you haven't already, they have local chapters.