Finally, how should I think about financing/equity/cashflow factors specific to SFR's? 

And/or, keep them forever.  

Plus, factor in much higher insurance and maintenance costs, not to mention the "the pool is dirty" phone calls. 

If the HML's are quoting you 10%, then factor in those costs when you run the deal analysis.

The most important factor is where you spend most of your time, but the other factors that are relevant include addresses on documents and proximity to various venues/people.

If the house is an obvious fixer and has other compelling factors, i.e. it's vacant, thus we know it's probably a pain for the seller, then we may give it a second shot.

I know there are a tremendous number of factors such as seasonality, pickup, quality of the listing, etc. but I'm currently working on going through things to put pen to paper to write out why.All that said, Pricelabs (the tool I currently use) has recently added a feature to their dashboard.

I love my work but I don't want to exchange hours for dollars forever and I currently have no retirement funds.

For cash flow, you need to factor in more than just the mortgage. 

That is what a 3% vacancy factor is.