Purchasing the 11 units will give me enough ownership to become the president of the association and reduce common charges.

You have cash flow of $700/month but if you can add a property that has the same flow or higher, wouldn't it be worth it to reduce your current property cash flow to add another property that gives you an aggregate cash flow that is higher?

I am struggling to understand how depreciation and taxable rental income should be calculated in the spreadsheet.As I currently understand it: Depreciation of property value (not land) can help reduce taxes on rental income.

For example, I used to buy bulk collections of Xbox 360 games when people sold them (like 20-30 games) and then sell them individually on Ebay.

What they fail to understand is that equity, due to it's opportunity value, actually reduces cash flow more than having 100% financing.For appreciation investors it is more of a game since they have already made their money.

End result negative 5% return.For this reason it is understood that equity reduces cash flow on a property it does not increase it. 

Very sad to hear all that equity is lying dead in your property likely reducing your cash flow to zero or less.

I am entering into a contract to make a bulk purchase of 10 Condo units in Arizona.

I am entering into a contract to make a bulk purchase of 10 Condo units in Arizona.  

Tracking all income and expenses on everything you are responsible for and review them regularly so you can hopefully reduce expenses and increase income.By the way, I'm now 60 years old and quite opinionated.