By no means do you need to ask every question but if you are stumped or left one tour thinking "I'm not really sure what happens after I check into the hospital" it can't hurt to browse these questions before your next tour or email your tour guide with additional questions.
Please also note this blog entry is based on a mother who toured hospitals in Rhode Island and not the greater Seattle areas. There are certain questions that don't necessarily apply and may have different terminology that stated in the attached blog. As in, I've never heard the term "Stork Dinner," on question 37.
http://www.tallmomtinybaby.com/2013/03/questions-to-ask-on-maternity-tour-of.html