Use "Property #1" to figure out if all of your assumptions are correct:  rehab costs, timing, refinancing, etc. 

You (or a county appraiser) can easily access these documents, then work backwards (making some assumptions about loan-to-cost ratio) to ballpark what a property traded for.- I have reviewed commercial leases--caveat: not nearly as many as other contributors here--and have yet to see one that caps uncontrollable expenses, which would include property tax.

If my assumption is correct, break even, how long before a positive cashflow is netted?

My assumptions: At least 1 on site manager and 1 FT or 2 P/T / On-call maintenance staff, with outsourcing of lawn care, snow removal and possibly items such as unit turnover (paint, flooring).I (and lots of my closest friends, business partners) fund 10% of this deal and I get a loan @7% for the remaining 90%. 

We ran numbers based on our agents rental income assumptions and thought it would work.

We ran the numbers based on our agents rental income assumptions and numbers worked though low ROI.

for $XX,000 plus the assumption of the mortgage in 2012.4) it appears there was no "real" assumption at least that the bank knew about, because in 2014 when the bank sold the loan to the next note holder, the original borrower was still named in the assumption5) regardless of the default, the mortgage sees to have had a balloon at the end and it matures next year.So my questions start with: A)  For short sale purposes, I'm assuming the only one who can actually deal with the lender is the original borrower, correct?

The downside is that to accurately calculate them you need to model a number of different variables and as a famous statistician said "All models are wrong, some are useful" If you don't have confidence in your modeling ability or you are too optimistic with your assumptions, the math will lead you astray. 

Spreadsheet Assumptions I tailored this spreadsheet based on my own situation, but I think it can be manipulated easily for other situations especially for others with W2 jobs.

The blog makes a few assumptions, but it's a pretty solid comparison.