Keep in mind over the last year that for much of that time you were prohibited from charging late fees if the property is under a government backed loan program.

There is a card program where you use it like LOC

I would recommend using some of the available down payment assistance programs that can cover up to $17,500 of your down payment and have no PMI.I think some of the best areas are, Curtis Park, Cole, Clayton, Fox, Globeville, Elyria- Swansea and West Colfax.

If you have cash, probably better to build them, get them rented, and then cash out refi.Does BofA have a construction loan program?   

Vacant Properties Software Programs ?

They have a rental program for non-owner occupants on 1-4 units.  

Once a month using a software program to actually help your business have a accurate history record is not a big issue with me.

(Reference: http://www.rurdev.usda.gov/SupportDocuments/CA-SFH-GRHUnderwritingGuide.pdf)There are other loan programs out there that may accept less.

There are a lot of government loan programs that have the sole purpose of getting people who have low credit scores or who are building their credit into a mortgage.

Different lenders have different programs and rules.