For the lighting of the Olympic flame, I reckon it will be a car chase around the stadium with some chav’s finally torching the car leaving it raised and lit on a plinth.
Go to the main bike shop. Guys are super helpful and can point you in the direction of the trails. There is a world cup DH track (with the most mental hip jump I’ve ever seen) but most stuff is nice technical singletrack. Just watch where you ride and it’s pretty sensitive in that area. The local guides have worked hard to get access.
It’s normal I’m afraid. It’s to do with the internal butting of the seat tube and is wider there to cope with the stress of the pivot near that point. Has been discussed on the Turner forum loads. The answer? Tough, buy adropper post (that is Dave Turner’s answer is basically).
You can be sat on top of the BT exchange, it still has to go down some crappy copper pair into your property. Go fibre if you want speed and reliability.