I don't have any restrictions on pets with the exception of 2 things: no dogs under the age of 1, and breeds listed on my insurance policy that are not accepted. 

Yes, Chicago has strict regulations for short-term rentals, including mandatory registration and zoning restrictions.

Downside is that there are many restrictions and laws to navigate. 

I'm wondering if the same lenders who financing STR's would consider Padspits.You may want to check this, but I would imagine that renting via Padsplit would be considered as a STR which have been highly restricted in the city of New Orleans, and the only way you can get a permit recently is to also live in the property.

The worst thing is that states and municipalities are using wildly inflated data that AirDNA and their ilk are pitching to create more and more restrictive zoning laws based on the perception of windfall host profits, further creating challenges to supporting our mortgages in a region with an already long 4-6 month shoulder season.

Many hoa's have restrictions / limits to non-owner occupants allowed in a community / building.

Best practice is to operate as an MTR and backfill with STR guests because if you open up your calendar to STR guests without tight restrictions, you're an STR.  

I know in California it is legal and the state acknowledges it however it does restrict the finder to basically introducing the parties and they can not participate in negotiations, etc.

Real estate activities are typically considered passive activities, and the IRS restricts passive losses to offsetting only passive income.

Of course, with all things, the answers to all these matters will depend on the circumstances.California tends to have more laws on the books and requirements and restrictions that it can be a good idea to form a CA LLC for out of state property so that you as a CA resident are covered, and to try to have your contracts fall under the purview of CA courts.