I understand that I can deduct mortgage interest up to $750k on my personal residence.

Many groups during Covid have switched to online only or a combination of online/in person events.

I know these guys personally and can vouch for them personally. 

Thank you @John Mason.Do you have personal experience with this firm or some you know is good and reliable ?

It's similar to how you report it for tax purposes in years where you aren't selling it, you report 50% (or whatever % is allocable to each side) as rental property and depreciate that 50% while the other 50% is your own personal residence and therefore is not part of Schedule E.

Buildium has this statement, hopefully your PMC knows how to generate it.You should be able to give your tax professional the 1099 and annual statement, along with property tax, insurance, etc. bills you personally paid and that's it.I think Buildium even allows the annual statement to be sent in CSV format, so you could just add the expenses you paid to that.

Since, you will have to do business with them on your properties on a personal level.

Approaching the end of my first BRRRR (rehab to be done in 2 weeks) and I'd like to reward my contractor with a cash bonus; I'm wondering what an appropriate amount of money is to give him.

You are looking to rent or buy a space with a partner to have a personal fitness business or just a class?

I would recommend choosing someone with the most forum posts and/or reviews that way you know that person is active