You're spun around, flipped upside-down, and confused as can be.

Very compelling, but have you considered

spoiler

Tankie is a term that specifically refers to one particular kind of communism

No, it's used to refer a wide, vague blob of vibes, just like the word woke. The people who use it can can do use it to refer to all kinds of communists, most anarchists, and anything to the left of Elizabeth Warren in general.

that try to impose communism through the use of force.

As opposed to the kind of communism where you ask nicely for revolution? Have you actually read any Marx? I guarantee he was not a pacifist.

You can be a communist and not be a tankie

By your own definition you cannot, let alone by a definition of tankie that describes how libs actually use it.