Newer homes seems to command something close to $1 sqft up to 1500 sqft then the larger home prices do not scale accordingly.

That's the only motivation I can come up with for why he would want to owner finance, he doesn't need a lump some and who the hell wants 3% interest when he could easily command 8-10% for an owner finance deal...

Unless rental income increases then when you come to sell it will be tough to command a higher price than you've paid. 

Not a bid deal, an amount that most mid to large banks can approve on a regional level, so not a huge chain of command to go through and the holding costs for the bank will probably be more than that anyway. 

I also plan on handing a bunch of those command strips/picture hangers to new tenants and requesting that they use those instead of putting holes in the wall.

Once stabilized units should command $500/month.

until you are big enough to command a team(team members making substantial money from you) just start getting help as needed.

Once you get more experienced and bring that experience to the table you can probably command a 50/50 split.

For example, a market that commands $300/sq foot-- an astute buyer would not pay a full $90,000 for 300 sq feet of incremental space in a 3,000 sq foot house but assign a lessor value.

-there are a few studies that have shown that green homes have sold for more than their non-green counterparts:http://www.washingtonpost.com/realestate/study-finds-that-energy-efficient-homes-often-command-higher-prices/2012/07/19/gJQAF4MiwW_story.html  I for one would like to see more studies done to validate these findings.