If you had your retirement funds in conventional stocks/bonds, diversified for age appropriate retiree, the recommend a higher proportion w/ age into the bonds making 3-5% APR and less in the stocks making 7-8% average over decades....then they say "it's safe to plan to live on 3-4% withdrawals"..... in any given year.

Fixing the same number of toilets isn't going to be proportionally more expensive, so that kind of expense will be lower as a proportion of the real estate value/gross rent.Am I on the right track here?

@MarieChele PorterThe great thing is...Risk is inversely proportional to ignorance.  

It's tough but here is some fun. 10 ways to appear engaged at your day job with you are building passive streams of income1) walk fast and move around frantically – general work areas2) don’t tell people where your are going on vacation (ie going to Dallas to look at apartments)3) don’t take calls in your car where people can see you4) don’t drive a fancy car to work5) attempt to look like your bring a brown bag to work… Say something like you are being healthy6) invest in a small compact laptop to analyze deals and emails & Google Drive!

Your deferred taxable gain is allocated proportionally.

If you have better supporting comps the appraiser will take a look at them or if the adjustments are out of proportion you might could get a little there.

Tiles usually crack on the spot that a concrete cracks after the fact, or are hollow by the touch, and it will be a problem until the house settle for good (depend of the soil and compaction etc, it can take over 15-25 years from the original construction).  

@Danielle Hoffman It will be difficult to tell foundation issues by %, it is like everywhere else, poor quality construction leads to issues including poor compaction of base/soil where the foundation was built, which causes foundation problems.

Your COC should increase each year as your rents increase and your proportion of your monthly payments towards your principal increases.

Certainly the laws of supply and demand take effect.If you have information that shows a detailed analysis of rental amounts and how they increase or decrease as a direct proportion to housing prices, then I certainly can evaluate that information and adjust my investment formulas.