1. It was jarring. I kind of give him a pass not only because of when he first wrote her, but in using that as a device to differentiate between the two personalities.
2. Hated it. HATED it. Made me roll my eyes and want to throw the book across the room. Over time though, I've given him a bit of a pass just because he had nearly died, gotten into a hurry to finish the series, and I think was working out some of his own existential junk by doing it. But it sucked. Really sucked.
The ending is letter perfect in my opinion which is ironic when you consider King's history. Roland's tale is a cyclical journey. He has to start over, but now with a very key tool added to his arsenal. With all of its references to King, I thought LOST should have ripped off the ending as an homage. A few episode build up where it becomes clear Jack is on a journey that we think will be completed, but when he walks through that door we flash back as Jack opens his eye, gets up to take in the chaos of the crash, but it's clear he has ________ added to his arsenal to get him closer to completing his journey. Could only have been better than what they wrote.
I digress. Glad you loved the series. I'm going to read it once more through before I die.