Because of that, the majority of people here prefer detached lifestyle (SFR) except in the luxury apartment and condo market downtown.

If they fill your units, they probably wont leave until the lease is up... because frankly any science major at A&M, Texas Tech, or UT doesn't have time for anything else but school.

It is pulling out the money that you previously put in.Once you're at a point where your money is recovered, and you have profits over and above - you're free to do anything with this money, probably in this order:keep a reserve for contingencies (vacancy, major repairs etc.)reinvest into buying more propertieswhat you call paying yourselfYes, it is arbitrary.

Student loans are a major issue3.

We fixed the major things (mold, replaced carpets and flooring, painted everything, fixed the sunroom etc.)

Your "primary purpose" of the trip must be for business and the "majority of time" must be spent on business.If you book a trip to Disneyland and then decide to look at rentals while you are there, that won't count.

They usually exhibit a “flat” growth curve with no major spikes or declines.

It seems you're familiar with DC, so the number you mentioned shouldn't make sense to you from a gut perspective, as there are hundreds of streets in DC where the majority of the row is 2-4 unit. 

What if the returns are better now, or when you retire and you get the majority of it?

They had major issues with lead times and hitting their deliveries which was annoying, but we have also experienced an issue with the large sliding window in our master bedroom (seems a seal exposure/draft issue) already within a year or so.So I won't be buying Crestline again, maybe not fair but that's my data point...