Saturday Morning Breakfast Cereal

Do you think its alright to use dumb and stupid? [...] I imagine Idiot is ok because it comes from the greek for common man.

It's not so much what words I think are bad, but what usage is hurtful or unconstructive.

For instance, thinking Trump is an idiot is a fine gut reaction to have to the latest dystopian headline, but I think his actions go well beyond simply having a low IQ. There are lots of very nice stupid people in the world who don't deserve to get thrown under the bus with someone who's actively malicious.

Or say you're arguing about something and think to yourself "Wow, this guy is fucking stupid." Maybe they are a stupid person, either by disability or lack of education, but attacking them over it seems purely cruel to me. It also undermines your own argument by creating an emotional distraction.

A thought can be dumb

The difference between calling an idea stupid and a person stupid is a pretty key part of context in my opinion. It's still pretty charged language though, so I hesitate to talk that way with strangers. I'm more free with people I know well who won't feel attacked.

Somebody cuts you off in traffic you say motherfucker and you feel kinda better for just instantly getting it out of your system instead of keeping it bottled up

I think you kind of hit the nail on the head there by using motherfucker instead of an intelligence-based alternative like moron or similar. But even if you do go after their intelligence in the heat of the moment, that doesn't make you a terrible person. Being able to later reflect on internalized ableism and how prevalent that language is in society is a good thing, imo. You don't even need to feel bad about it exactly; I just think it's a good thing to be conscious about your internal thought processes.

you don't sit there and go through a Buddhist podcast about forgiveness and suffering and think about how difficult life must be for that motherfucker that cut you off, and how she probably was distracted by her kids or stressed about something.

I think you should though, sometimes. (You don't have to be perfect all of the time.) This is part of cognitive behavioral therapy and can help alter your thinking patterns in healthy ways. Being empathetic towards others is not only good for them, but also good for you.

(I realize in the course of this that I've been intolerant of people banging their own moms, and I'm okay with that position at this time.)