visit to london, a few questions

I'm going to London with my wife on a long weekend in mid-february. I plan on taking my D300 and a few lenses with me. I have a few questions I hope someone here can answer.

I think our daily schedule will be something along the lines of leaving the hotel, seeing some sights and visiting a few museum, have dinner and then return to the hotel. Can I take my camera bag with me into museums? Or are there lockers or something where I can leave it when I visit the museum?

How about if we go and see a show in a theatre somewhere?

How is street crime in the tourist hotspots in the center? Anything to worry about?

Any tips on good photo locations? I have an impression in my mind that large parts of the center of Londen are from the early 1800s or later if there's any older parts with interesting little streets and alleys I'd like to shoot there as well.

Further tips are of course apprieciated very much.
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Don't wait for the Nikon D-whatever, have fun now!
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