You can browse through them through my profile to see if you find anything you're looking for there.

General rule is that you may get some things like improved general software interfaces, more experienced professionals (some people get REALLY specialized in certain topics, it's crazy to see sometimes) Also, the option that if you do have something unexpected come up, they might have more staff capable of handling it so you wouldn't have to move around at all.

Just browse this forum, see who answers questions and how, and contact those people who you want to work with.

CPA's still have to interface with people and get/keep clients, i.e. your sales desire. 

Surely there would be some way to interface directly with the medical schools.

You may want to browse the Syndication Forum here on BiggerPockets for some insight on the current state of that market.

Just browse the forum, see who answers tax questions and how, and find people you want to work with.Then contact them individually.

You can't just browse online like you're swiping through a dating app and expect to find what you need.

Once in the app it looks just like any other Cable TV interface. 

I’m curious on whether properties are grandfathered in because I haven’t seen any STR’s with one in them yet as I browse listings and walk properties.