So if I understand this correctly, by qualifying to extend the 5 year rule to 10 yrs, $250k if single or $500k if married of proceeds from this sale would be exempt from capital gains? 

I agree with Patricia, but there are always exceptions to every rule.

You can find duplexes under $180K in C-class neighborhoods, in decent condition, that meet or exceed the 1% rule

The 50% rule is about right. 

I think demand is decent.If you're looking in a flood zone you'll definitely want to understand the FEMA 50% rule.

However, I have found trails of information on the internet and FHA-type websites indicating if you relocate due to work, that you are not bound by the 1-year rule once you begin at your new place of employment.

If there are items of value left behind, or even personal items of sentimental value, I will follow the abandonment rules to a "T" to avoid any legal issues.

In Columbus, it's pretty straightforward if you want to sell a property. 

I will not comment as to the tax laws and underlying rules - that is a discussion you can have with your tax advisor who presumably you are paying to help you.What I will do is provide practical and business guidance on tracking time.Firstly, there are apps available that can assist with time tracking where you can specifically detail your time, who you met with, etc.

I agree with the time/effort rule.