Monthly interest only payment amount will be based on if it were divided over a span of 20 years but only paid up until the balloon payment is paid? 

To no surprise there was an active waiting list from dozens of other people which spanned back 9 months. 

A 2.5year span is a very short timeframe, however I'm sure you can appreciate the astronomical difference that obtaining triple the returns over a long period of time will do to the final number when it comes time to retire.

In the simplest form, you can look at long term historical pricing to see if/how long/how steady the history of price and rent appreciation is ... there WILL be some fluctuation as RE is somewhat cyclical and nothing ever goes up in a straight line always, but does the neighborhood and surrounding neighborhoods have a long term track record, spanning several up/down cycles of appreciation and rent increase?

The metro had a double-digit growth spanning a total of 21 months, from July 2014 to March 2016.

It's nothing against them but they're using radiuses that are miles and often span different neighborhoods. 

But it listed things like A/C, water heater, roof, etc, the expected life span of each, the estimated age of each, the replacement cost of each, and the amount of money that should be set aside each month to be prepared for the life-cycle replacement.

Would expecting a 8-10% appreciation in a span of 3-4 years and a positive cashflow every month be too much in these areas?

Facebook retargeting is one of my favorite ad sets to run because you can use it to lengthen the "life span" of colder leads that are coming into a website from AdWords, direct mail, or even organically.

A truss will usually clear span from outside to outside walls.