Currently I and my business partner own 2 town houses, one is a 4 bed 2 bath.

You could also bring on a business partner that specializes in sales/marketing to lead that side of the business

Publication 15, Employer's Tax Guide, says only this much:...Payments for the services of a child under age 18 who works for their parent in a trade or business aren't subject to social security andMedicare taxes...No definition, and IRS publications are not really law anyway.

Today we basically run two businesses, one in REI and one is a brokerage team.

Is it worth to invest and learn from their program in order to start my co-hosing STR side business just to get some extra money monthly?

This will be based on the personal details of your business.

Quote from @Paige Corsello: Hi Bobby, the majority of my business is in Pittsburgh, PA and Florida Paige I can go 80% cash out in PA In FL I can go 75% cash out and 80% rate and term

A $12k commission may actualy break down to less than minimum wage with brokerage commission splits, taxes, insurance and all expenses factored in.That's why agents are careful to make sure they are going to be paid for their work, if they want to stay in the business.

I have a rule , never do business with family or friends .

You could sell the property at the beginning of the year and buy a property/place that property in service (and do a cost segregation study in the same year).