Between the two, you’ll cover the vast majority of guest traffic without adding unnecessary cost or complexity.

You'll lose your primary residence homestead exemption (which caps property tax increases in Florida), likely pay higher mortgage interest rates or struggle to get financing (owner-occupied mortgages require you personally to own and occupy), and create unnecessary complexity for minimal liability protection when you're living there anyway.

A loan can work if she prefers structure, with IRS-required interest, but she could forgive parts each year under the annual exclusion.For a one-time $200K transfer, trusts or custodial accounts are usually unnecessary unless her estate is near the threshold.

I would also see if your lease language speaks to you paying the bill and charging them, or imposing a late fee based on the water bill.

The guests either says heck no I am not giving Airbnb money and reverse image search the listing to book direct or the guest (like me) hates unnecessary fees and books something somewhere else or not book at all.

This is technically unnecessary leverage since you can sell for cash with zero taxes. 

For example a price below where I think it will sell for, attracting more Buyers, but not too low where I'm doing unnecessary work filtering out Buyers who don't understand the market conditions.

Track every expense: Every dollar spent on purchase, rehab, or closing costs adds to your cost basis and helps with depreciation, which can reduce taxable income in the future.Build your team: Even if you know contractors, having a CPA who specializes in real estate investing can help structure deals, plan for taxes, and make scaling smoother.Starting with these basics, such as organized records, smart leverage, and the right guidance, will put you in a strong position to grow your portfolio without unnecessary surprises.

That still doesn't do anything about the imposing HOA, which I had not considered at time of purchase because my intention was never to hold, it was to flip, so I didn't do a cashflow analysis on it.

Speak with a lender and understand the costs associated with purchasing your first property keeping in mind the reserves you should have set aside for the real estate + money set aside to enjoy life without any unnecessary financial stress at this stage in your life.