The PO Box mainly won't get used but in future I plan to use the address with any tenents.

Then do a cash out refinance and move onto the next.But my main focus is HOW am I going to expand fast to achieve my goal?

Aggregation Election.You can elect to aggregate all of your real estate activities into a single activity for purposes of meeting the material participation requirements.

I'm hoping this leads to me avoiding a lot of those early mistakes, but we'll see how well that actually holds up.The main thing I am excited about with Bigger Pockets is hearing opinions and thoughts from a wide array of people.

Quote from @Patrick Shep: if you’re figuring out the land value for depreciation purposes, can I use the Fair market value for the land? 

Did you miss or purposely skip over the parts that didn’t suit your argument?

if the property is in Oregon they need state MLS and NMLS registration for ANY loan on a 1 to 4 unit regardless of purpose.

My main goal?

For the remodel I am thinking of extending the main home (which would make it "L" shaped") to incorporate the detached carport and detached bedroom/bathroom.  

Quote from @Evan Polaski: I mainly disagree with number 1.