I do however manage 300+ rentals in the area and help our investors find new properties on a regular basis. 

Have a spreadsheet or accounting software and reconcile your bank, pm, and cc statements to the books regularly.

The return would be great for you. as for the other house, still chase it with just the down payment and regular conventional loan process. 

Not sure if that's what you're asking, but I don't regularly do it either.

I have aspirations to move into larger properties and found a 40+ unit multi-family that I'm considering putting an offer in on with a few partners.The numbers all work out, the neighborhood is what we expect, I have walked the property and it's in pretty good shape, but the once concern I have is, the seller is unable to produce any of the repair invoices for work they've done over the past 5 years of ownership.

One thing that I think I have learned that seems to hold true is that because my day job is moderate six figures and I plan to keep my regular job for a long time, that I should plan to get more of turnkey rentals and use property managers.

2nd, how do you decide what the monthly payments are and does the entire payment go toward the note or can it be structured like a regular mortgage to where a portion would go toward the note and the other part goes toward interest?

Is 3% too high for a regular agent when I am buying multiple properties a year?

As I use the bigger pockets calculators to analyze potential deals, for the extra upfront money required to get into the small apartment deals, it does not produce extra cash flow in comparison to what is required for me to continue with duplexes. 

I live in Fredericksburg but grew up in Woodbridge and am still in the area regularly.