I'm pretty picky about my vehicles, and I'm not the type to leave a dent alone, however in this case I might.
For starters, there's the headliner issue. IMO, body shop guys and mechanics pretty much are universally terrible at removing and replacing interior panels correctly. I was a car audio / security installer way back when, so this is a pet peeve of mine. It's not difficult to do, it's just that most of these guys don't care. The only thing they are usually worse at is wiring.
Case in point - I bought my wife a CPO BMW X5 last year. They had to drop the headliner to remove some filler strips on the roof that needed to be repainted. (Which I didn't know about until after the fact....long story.) I'm not exaggerating at all when I say that they reinstalled every single interior panel wrong. Broken clips, panels forced into place without the clips being lined up, panels put back on in the wrong order, lights not installed right, you name it, they f'ed it up.
The other issue I'd be concerned with is overspray. I can't recall ever seeing a body shop repair where they didn't get overspray on something....that also drives me nuts.
My first step would be try one or two more paintless dent repair guys to see what they say. Even if they couldn't get it perfect, I'd still rather an imperfect PDR repair over filler and paint.