Anyone trained vital points to high percentages? Did you notice any change in
damage or critical hit ratio? i'm just thinking this skill probably does more
than just enabling you to use acupuncture.

To my knowledge it does not do anything damage or hit related in monk guild.
At high percentage it enables 'dianxue' emote but that's it. If I'm wrong,
please correct me, but if not, then I really wish that something would be made
to it...

It does help ... sometimes you can get special combat message (i dont have
exact exmple) which says somewhat like : finding Blabla's vital points you make
your attack most painful
and such... so yes - you get something like "Vital Points Criticals", which do
more (according to messages - much more) damage than usual attack.