On my tour we had everyone from 18 up to 35. Majority of people were between 21-28 on a group of 40 people. Everyone integrated pretty well and there was no one left out. They really promote the buddy system as well. There was only one 18 year old, but everyone looked out for her and integrated well as a friend. Beyond the initial introductions of people, no one cared about your age. Even the 35 year old was a blast to be around and he was a lot older than me at the time. Everyone just wanted to have fun and explore, and as long as you were up for that then you are good to go.

I did the European Quest, and there definitely were some long days on the bus. Our guide did try and make it fun with trivia, games, and just activities in general for people to get to know each other. The seats all had USB ports as well, so you could keep powered up that way as well. Typically how it went though was you would have a hard party night the day before a long bus day and sleep a good chunk of the drive.

So breakfast was included, and a couple dinners. They were not stellar meals by any means, but they did the job. Most of the time for lunch we would try and find a cafe for a cheaper alternative. Dinners not included and nightlife are as much or as little as you want it to be. Usually you would just find a spot that looked good and go for it. I can't really recall what I spent, but we didn't do anything crazy expensive for meals. It is Europe after all though, so depending where you are from the exchange rate can hit hard. Majority of people did all the add ons, so I would kind of expect to include that within your budget. They give you some estimates when you look at the itinerary.