And there is nothing wrong with pursuing a cash flow strategy... nothing guarantees the long run rate of return on any investment; which after adjusting for inflation and other opportunity cost may not be materially different anyway.

As a project manager (and if you are running your construction projects, or an owner doing some of the work on site, you are THE project manager) you need to have a plan for the entire project in 3 different areas: Scope- what work is to be completed on the project to achieve the desired result, Schedule- a reasonable expectation of time required to accomplish the scope, And budget- the money needed to actualize the scope within the defined schedule(also known as the project constraints)There are many ways to deal with all of these constraints and different projects require different strategies, but the important thing to remember is that the 3 constraints are tied together- if one changes, the others need to adjust as well.

I will adjust the numbers.  

What are your baseline numbers and how do the idiosyncrasies of a given deal affect these numbers (if at all) and do you adjust these assumptions for different submarkets/markets? 

Adjust your lifestyle as needed.

I like to be informed of the long run of the market before jumping in, and I hope to bring that philosophy into real estate.How granular can the data get, say for the metropolitan area level, for metrics such as inflation-adjusted rent (for 1 br?

There is definatly an "adjustment" coming. 

Why not get all your overheads in one year then divide it to any/all properties, have a pre-set high rate to charge per property and adjust it at end of year. ie if your overhead last year was 10% charge 12% per property then if it goes 8% LP gets the 4% additional at year end.

Just a quick add if you are considering NPNs, they are cheaper, but they are also much more work intensive and I would caution against pricing a NPN based on the view that you expect the borrower will agree to some sort of modifiction/DIL.

(I have one lease, where, after a year of almost-on-time payments, I realized that the tenants, two sisters, simply needed an adjustment for their work paydays - their rent is now due by the 10th.