Honestly if you hire someone in house , buy a van or truck , ladders and misc tools , give them  40 hours a week , pay them around $ 20 an hour for someone who is pretty good add on workmans comp , insurance etc .  

The only disadvantage I'm aware of is that they are a bit more difficult if the owner wants to alter the home, add-on or whatnot down the line. 

Not only was the only access to the back deck from inside the house THROUGH a bedroom...there was this monstrosity of an add-on bath:The steps to the right go up to a shower stall.

The closing costs you mention on the refi's sounds high (4k each), unless you're paying the 1.5 point add-on for investment property loans (as opposed to bulding it into the rate), to keep the rate lower (may be very reasonable to do if you plan to hold for 5+ years).Get as much of the property purchased, and the loans in place, prior to leaving your employment--I'm sure you know this.

If this really a rehab and add-on, or is it a scrape to make it similar to the 3/2's?

While adding the trap you might want to add one of these, too. http://m.homedepot.com/p/Oatey-1-1-2-in-PVC-6-DFU-Air-Admittance-Valve-39230/205395535

Have had terrible experiences over the past several years with both Keller Williams (non-responsive, charges all sorts of extra add-on fees) and Monument Management (a horrible company that was increasingly late forwarding rent payments, had huge personnel turnover, terrible communications, and probably worst of all, they doubled and tripled actual cost of repairs!).

I can always add one later.

If anyone wishes to add on this please feel free.

Best Regards,Kody