Question- there is probably a cool, professional way to word it, but I was wondering:  if I wanted to work/partner with a friend of mine who has the funds -but none of the time, knowledge, or contacts to find and manage properties- I would find the properties, find renters, and manage the property, and he would lay out the %25 down payment.  

You may need an architect if you modify the facades (like windows positions or numbers), the interior layout (like touching load bearing walls) or foundations2.

Doing the latter would improve my cashflow from that paid for unit from 1000/month (for the paid for house left as is and cashflowing) to about 1250-1400/month of cashflow with the cashout refi used to leverage 3 more properties.I intuitively understand that the refi method will in the end make more money, since I'll have increased my house numbers by 3 (from 3 to 6), adds ~450K to my portfolio in house values (each being roughly 150k) and will have renters paying down the mortgages and also covering taxes and insurance as well.  

The second building is have layout of dubplex 600 + 900 sq ft, but need all the interior.What i am thinking is to turn the main building in to a 4-plex and use 1 unit for my self. the duplex would be 2 unit.

Most seller representation contracts specifically lay out what happens in cases like this.

Check comps, not just for price, but for layout and finishes. 

For me, I lay out a very specific scope of work and then create a draw schedule based upon completed work that we have agreed to in writing.  

You don't even need to tell them you want to buy their house counter-intuitive, I know!  

Around $1.6K in tuitions, app fees, etc.  

The layout is a residential single-family home that has been subdivided into three units consisting of 2 x two bedrooms and 1 x a one bedroom that is located in the "basement" of the house.