Hey Harperb,
I've been looking through posts here for a few months and haven't once found anyone with all the same symptoms I have which is what caused me to stop taking Omeprazole as i thought doctor must be wrong, I'm still going through tests so i can't say 100% what my particular problem is.
Your post has made me quite happy (not because it's good to have some problem that makes you miserable

) but because the mouth issues are exactly the same as i've noticed the last few months too, I don't have an answer of what's causing it for you as I haven't mentioned it to my GI yet, due to go see him on the 7th, if i find out anything helpful, i'll be sure to come let you know if reflux is indeed the cause.
Hang in there..
Secretrelief.