Yes, that's the Olympic Park, not the highstreet or the local train station. You could buy tickets just to go to the Olympic Park for the day (would've been a bit pointless if they let anyone in) it was part of the Olympics.
I don't understand that. So you weren't allowed to go to the shops...
I can't think of another example where you have to show your ticket to someone until you're going in, and that includes the Olympics. Once in the ground, I have no problem with being asked to show my ticket, but what about (for example) when the game is in Brighton, and Palace fans are in a...
Firstly, if they are members of public in the street, then who says they've even bought anything (ie, a ticket) for there to be any conditions of sale. Secondly, you can't put anything you like on the conditions of sale, and it be lawful. You can't, for example, tell customers that if they agree...
That's all to get in, and once you're in. They do not have the right to search you etc when you're not in the ground/going in etc.
But if you fail to produce a ticket because you don't have a ticket, then you haven't agreed to the terms and conditions on a ticket you haven't bought.