If you are worried about the work load, I would say your best bet is to start interviewing property managers to see if you get a good feel from them.

I'm familiar with IRR, and I could see it having a place as an output in my analysis.My main goal is to capture the most commonly used metrics -- and based on the people I've talked to, books I've read, podcasts I've listened to, and blogs I've read, the most commonly used ones seem to be cash flow, CoC Return, and Cap Rate -- and allow a person to compare many properties using all of these metrics simultaneously without any a priori assumptions about which ones carry more weight than others.

At this rate it will take 4 days just to load one property.

This is no load, low expense ratio fund, and if you are concerned about the market just spread your investment over few months, use dollar cost averaging strategy. 

Different investors weight the four categories differently.

If you are dealing with an addition built on 12" beams (or if the original foundation is old and not built to current standards), the repair company might not be able to push the piers down to refusal depth or psi due to the beam not taking the load, thus leveling it, but not guaranteeing it will not continue to move in the future, thus not providing warranty.9.

Believe you me, this guy is worth his weight in gold.

Talk with people you trust, understand how much they know, weight their advice accordingly and make your own decision.

Do you think that in 20 years you won't have a boat load of equity and net worth?

It’s like losing weight.