Sorry you're having a bad experience/not the experience you want, but I'd say at the outset that nothing you describe sounds terrible/terribly out of the ordinary. A lot just sounds like a personality difference.
But: 1. if the artist is a true pro it's not so important about the planning: she knows what she's doing. the discussion is more on you to ask ask ask. (That said, I'm doing traditional Japanese where you only pick the subject of the tattoo and everything is up to the artist. So I come from a very different perspective on this.) 2. "touch-ups" in the context of still working on a large piece are different than if it were complete and you were going back months later. They're often necessary, and I would just chalk it up to getting the perfect piece. 3. $250 is a loooottta cash but yes that's what you'd pay for a unique top quality piece. Without seeing it it's hard to judge whether it's truly cookie cutter though, you know, rather than your feeling bad about it given the experience you're having? 4. yes it'd be an issue, and don't do it..... 5. finish what you started. You have to finish things in life.
That's my 2cents, others may disagree/have different interpretations.
Cheers and good luck!