Why 3 lights? If you’re not actually planning to be out after dark surely a little blinky light as a ‘just in case’ is all you need. Stick it on the bars. Even if you carry a Maxx-D or whatever, put it on your bike!
No wallet, £10 and a card will cover it, what use is your Nectar card and a Blockbuster video membership?! Why coins separately? You’re not gonna need to pay for parking.
Leave the Red Bull-esque drink and some of the food (do you need any?), if you’re that desperate you can buy some.
You don’t need waterproof trousers. It wasn’t raining when you left, or you’d be wearing them. If it starts pouring a jacket will keep you warm, trousers can be nice (I imagine, never owned a pair) but far from essential.
Get a small cable lock, it’s presumably only to stop someone walking off with your bike while you’re in a shop, s D-lock will weigh a ton.
Do you really need your camera? Phone camera if you see anything you have to photograph?