You would need to contact the company LivTours. I simply told of my experience as a customer.

Yes it does.

Definitely worth contacting them. The restriction of 6 might also relate to the number allowed in the colosseum underground as its a very small and cramped space so they won't allow many people down there at one time. As the others have said this is a really excellent company so sure they will do their best to help. I can't recommend them enough and the underground tour is well worth doing. Have a fab time :)

There are some parts Inside the Colosseum that have steep steps that may make navigation with a large stroller difficult for 1 person. I cannot comment on whether a stroller is allowed inside, but thy ex tour itself was awesome!

Yes. We did Palentine Hill first-which showed us the forum from above (we weren't allowed to go back into the forum afterward at ground level). Then the Colosseum. We entered through a side gate, which took us to the elevator to the sub-level access-which was very brief, but informative (and it just like the arena floor is a very small section). Then we finished out the tour on the arena level. They took individual pictures of us and group photos. They allowed us some time out on the floor, then took us to a seating area off to the side where they talked some more about the events/Colosseum, then we as individuals were allowed to stay as long as we wanted in the Colosseum looking around through the upper arena, and then exited ourselves.

If it were me I would click as an adult to secure the booking. He's more an adult than child at 16, and there is no price difference. They may discourage young children, and personally I would agree. This is 3 hours, lots of walking, but awesome. No place for young children and we are paying a higher rate for a small group, quality tour in a very adult environment.