Grain of salt: I'm not an expert, but just a guy who has (successfully) rented out bedrooms in two different condos I've owned as my primary residences in Austin, TX and Atlanta, GA.With that said, it's my understanding that usually, no, there's no special permit you need in order to rent out a room in a HOUSE.

Sometimes you can get rare  coverages included with special endorsements.

They sleep two adults each, not large groups and  were designed by a well-known firm that specializes in energy efficient homes.  

Finally, I want to give a special shoutout to Diego Corzo who I reached out to after I heard his episode.

For me I will very likely hold all my rental properties indefinitely and have them ultimately pass through my estate so all taxable gain (attributable to both the price appreciation and depreciation taken) will be wiped out so an IRA would only be a detriment for me. 

Is there anything special about it?

There will be so many evictions I predict landlords will hire lawyers who don't specialize in evictions to handle eviction cases. 

Because I have more than 2 years of equivalent real estate experience, I am eligible to sit for the brokers examination.I’m trying to figure out if it will be worth it, financially, because it would take me at least 3 months (application processing time is minimum 10 weeks and then I’d have to study for the exam).A special thanks to all who have been patient and respectful responding so far.

I don't really understand what was special about the last 12 months (according to her narrative the tightening started before Covid 19) then the years prior to that.   

Tax issues within SDIRAs is a highly specialized area of tax law and you'll want to make sure your tax pro understands the nuances of this.