This will obviously not work for extremely common names, but I did test properties that I have been mailing and the owners are fairly easy to find on Facebook. 

It makes more sense to spread it out over more properties even if I spend a bit more on the purchase price. 

It is at this time that I get a “sense” of that person.

This scenario comes down to numbers and what makes sense but for me I think putting less down to buy works well for keeping cash in your pocket for future investments/ rehab or maintenance.

Is this a common practice to sell half of a duplex for the price of SFHs in the area of approximate size?

I like SFH since they make sense in my market and I don't want to move, turn over my portfolio to someone else or compete with some super-conglomerates in the MFH market here.

I recently purchased a twinhouse (just one side) and was wondering if it would make sense to purchase the connecting side and convert them to a duplex?

Name.. date of birth... minor...Any children are occupants.. so 3 adults and 1 child is 4 people.. so if your occupancy is set for 3 people the child would make them over occupancy and they would not qualify for the house.Set occupancy level and make sure they know they can not add another person to lease unless someone would move out and that the new person would have to be screened and qualifyCO signers make no sense in this.. 

We commonly call this a partial exchange.  

I know there are some places where SFR make much more sense than condos, but in my particular market, both are pretty accessible.