So then those happen you will be given a assessment and charged for your share of the bill on top of the monthly HOA Fee sometimes upward of 10s of thousands of dollars.

Is there a certain calculator tool or spreadsheet you use to run specific criteria to assess best cashflow?

Realize all of the above are not mathematical, so its your "assessment".Then, what's the answer.Lets say your future payoff is $200,000 in 15 years. 

And she says that most of her Section-8 renter never move out, which means she doesn't have to continually have to be assessing new prospects to be renters, which can take up a lot of wasted time, as well as lost money, of empty Rentals, while waiting for high-paying qualified renters to appear.

This means in order to avoid paying rent, being assessed late fees, or being served with eviction notice, you have to notify the landlord in writing or verbally of your economic impact and do so within a certain timeframe.

Would all real estate holdings be given an assessment at year-end?

I looked in the city records and they assess the property for 500k but the owner is asking 550k.

If you want a software to collect dues and assessments, provide reports to the board, communicate with members easily individually or en mass, I recommend Smart Property Systems.

When (if ever) was their last special assessment? 

We will have a couple waterproofing specialists to assess the issue but my agent said for sure they would recommend doing a drain.