Reporting the mortgage interest on the return should be done with care, as the IRS does not have a copy of Form 1098 under your SSN (or EIN if business) reporting the interest.

TLDR: It was a fantastic workshop that will enhance my business, but he pitches his Big Dog program that costs anywhere from $20k-$60k.

To ensure you can apply the tax deductions against ordinary/active income, you have to materially participate in the STR business.

I have come across several companies like Legal Zoom, Zen Business and many others, some which I think want to overcharged me.  

Or maybe your family business is property management ?

I work with some of the best in the business.

He wants to use the 50k to jumpstart fix and flip business 

While demolition costs are nondeductible, a taxpayer may claim a loss deduction when the depreciable business property is retired from use in a trade or business or from use in the production of income.I would strongly advice talking with a real estate focused accountant here to help guide you.

In general though, you're able to directly offset your income from the active rental activity with the *losses* you take from the business, but once the business becomes profitable, this would also add to your taxable income. 

People like to do business with people who do business, present a good deal, and you will have a long term buyer to work with!