My W2 income is >$550k/year, if I build an RV/Boat storage facility, will my storage business expenses/losses be able to reduce my W2 taxable income? 

Do you have the skills needed to manage it well and prevent losses?

And a bonus tip, get black out shades and mention them prominently.

Before I purchase an insurance policy I wanted to seek some guidance on the best way to proceed.I received 1 quote so far for a HO3 policy that has 600k+ of dwelling coverage, 70k of additional structure, 450k personal property, 200k loss of use, 500k liability, and a few extras like equipment breakdown, water backup, service line.

Why did your CPA suggest that you need to break out the income / loss by each unit?

When you do buy a property, will you be prepared to manage it properly and prevent major losses by making rookie mistakes in the most heavily regulated state in the union?

If your goal is for active gains (w2 income and biz income) to be offset by the losses generated from your property, you need to do 100 hours material participation on the short term rental, and it must qualify as a short term rental by being rented out for 7 days or less.

Loss Information. 

This is especially true if the property requires significant upkeep or if the heirs live far away.Owners of Distressed PropertiesSellers who own homes in poor condition and can't afford the necessary repairs may prefer to sell as-is rather than invest time and money into renovations.Landlords with Problematic TenantsLandlords who have been dealing with problematic tenants, frequent vacancies, or costly property damage might want to offload the property quickly to cut their losses and avoid further hassles.Owners Facing Major Life ChangesSignificant life changes, such as health issues, retirement, or downsizing, can motivate people to sell their property quickly.

Even if you take a loss on your investment by getting out, it's probably better to part on good terms than having to lawyer-up.