As a K poucher I drink over 2 quarts of coffee a day...1 brewed + a large number of expressos and instant at night...all so that my pouch runs smoothly and without a hitch...they brought me full thermoses 4xs/Day to my hospital room post op pouch creation explaining that it helped to keep things liquid and running.
Been 35yrs and I still do it. It works less effectively than in the begining but still does the job.
Our pouches are the same (except for the exit) so it should have the same effect on yours...not sure how much you can drink before your output will turn to water but you can find your balance.
As for chocolate, dark is fine but milk in excess upsets it and effects the output adversely...so does soya. I do fine with ice cream in reasonable quantities (but I am rarely reasonable).
Everything is very personal and each pouch is different so it is trial and error with each food and each person.
Sharon