Or „get the XYZ outta here“ (fill in the blank with an obscenity). That’s a strong „go away vibe“ too.

Yes, buzz off is the rude one. Same as „get lost“. „Drop dead“ is even worse.

Buzz off is moderately rude, it's like saying take your annoying sound elsewhere. Get lost, go die, bugger off, fxck off, p!ss off, sod off, go to hell, etc sound extremely rude , unless if these are used in a self - protective way against evil - intent, super - invasive people..the polite way or the less rude ones would be, please leave, please stay out of (something), please give me some space, I'm tired of you, etc..adding the word " please " does diminish the harshness.

Yes, "buzz off" comes across as rude. "Please leave" is more polite, but still comes across as a bit rude. In general, we'll want to avoid saying variations of "go away" to the other person directly. Examples (i.e. It's your fault that you can't keep humoring them): If someone is trying to get us to answer questions for a poll, we'll just say "Sorry, I don't have time." If someone is trying to sell you something: "Sorry, I'm not interested", and keep walking. If someone keeps talking to you: "Sorry, I have to go (I'm late for a meeting/appointment, someone's on the other line, etc.)."

And there’s only one obscenity that fits that last one, that starts with „f“.