Your question in (1), my simplest answer is this is why you're not ready to be a Managing Broker, your lack of knowledge, insight and comprehension in this regard. 

For that reason I built a full-functioning cash flow model taking into account hard money, the mortgage refinance and all relevant operating expenses to assess monthly cash flow.

You should know how you can contest your assessed value, especially if you are buying the property for below current assessment.You should understand if there are any tax abatements available today or in the future.There are real estate tax consultants in basically all major markets, or your real estate agent can likely help with some basic questions, as well.

This book was released in 2019 but I found it to contain a lot of great information on voucher programs.https://www.amazon.com/Subsidized-Comprehensive-Government-F...

For water, is it best to hire a plumber to come out, turn on, and assess?

I've been using Avail to generate leases and collect payments from guests for my MTR but I don't think it has comprehensive enough features. 

Thorough vetting is absolutely essential in private lending to mitigate risks and protect your investment.Here are a few additional tips to enhance your due diligence process-Assess Their Exit Strategy: Whether it’s a flip, rental refi, or sale, make sure their exit strategy is realistic and aligns with market conditions.

**Risk Assessment**: Lenders use the DSCR to assess risk.

While condos might be all someone can afford to owner occupy or invest in enter at your own risk and if they are talking about future special assessments you will likely scare future buying prospects away. 

Perhaps a strategy to explore would be to buy in cash, exploit the buying power and get a better deal, stabilize the property over 12 months, have a better assessment of the properties expenses, then finance the property.