Just did this tour also a couple of weeks ago, let me see if I can answer the ?'s for you.
No, did not tip the tour guide and no-one in our tour did, about 20 people.
You do not have to wait in any lines and you ride the Jungle Cruise and the Haunted Mansion.
Our tour guide was Rae(sp) nice lady with lots of info.
We did go underground and did not spend tons of time there, maybe 20 minutes. Honestly, wasn't that impressive but neat to see.
We went upstairs on main street into the emporium and saw some of the offices up there. Some of the things on main street were pretty cool, behind the scenes was neat there.
No castle involved.
You eat at Columbia house and they give a menu to choose from in the beginnng of the tour. Food was pretty good!
Get to see backstage area where the parade floats are kept.
Hope I answered all the ?'s.
Be sure to have all of your ?'s ready, they will answer anything you've ever wanted to know if they can.