Yes, definitely ask for ketchup, lot's of refills and also a longer straw. Also wear a shirt from some other theme park and tell your server about the great day you had there.
Actually, someone once had posted a whole list of things to do at Whispering Canyon that will prompt a response from your server. I can't remember if it was on this site or All Ears. However, there was a caveat to not literally take the list in with you and try out each one line-by-line like a checklist.
So much of your experience at Whispering Canyon depends upon your server and how into the whole act they are and how busy the restaurant is. Per the food, we had the Canyon Skillet (AYCE BBQ ribs, pork, chicken and brisket with the fixins' served family style) and thought it was pretty good.
If you have young kids, they'll love the stickhorse races around the restaurant.
Don't forget about the ketchup.