Any Professions NOT Used In Films/TV Shows For Lead Characters?

Nope!

Mohel

Petrol pump attendant
Travel agent
Parking meter inspector
Restaurant Inspector
Food Critic (The Trip doesn’t count)

Johnson, Navin R. (The Jerk)

My Big Fat Greek Wedding (not her job at the start, but later on)
More engineers - Primer (they appear to be electrical engineers), Flash of Genius (the story of Robert Kearns).

Hobo With a Shotgun

I thought that in Cliffhanger Stallone was working as a forest ranger after the incident opening scene, but maybe he wasn’t.

In my location, and with very few exceptions (such as judges and Members of Parliament), only lawyers can be notaries public.

This may not accord with the experience of our friends in the US; but I would suggest that as lawyers were mentioned in the OP, and notaries can be lawyers, then notaries are represented by the many lawyer shows.

Interesting - Wiki lays it out

Being a “Notary Public” is very different animal from country to country

Goober and Gomer Pyle - Andy Griffith SHow

Forest ranger - Dennis weaver - Father - Gentle Ben

Professional hunter (or poacher) / Fishing guide - These are hugely represented in Outdoor TV shows

Re TV shows Daniel Boonewas a professional hunter and guide

Bilko was in the motor pool

Torturer?

How about Roadie?

Mark Zuckerberg was not a UX designer and Facebook’s first UX designer, Aaron Sittig, was not present in the film.

Yogi Bear.

Jeremiah Johnson.

Bicycle Repair Man.

Nah, I think this one is actually pretty common. For example, Closet Land and Sunshine are both set in police states and the lead actors (Alan Rickman and Ralph Fiennes, respectively) play interrogators whose job it is to extract information by torture. There are probably also a lot of gangster movies where one or more of the lead characters are thugs who torture people on orders of their bosses.

Funny sketch, but I don’t think one sketch counts as a lead character in a TV show.

Fine, then—I submit for your consideration The Wright Brothers. (Or even The Wright Brothers, another biopic of the same name.)

Having said that, both Dwight and Angela on The Office are Notary Publics.