if we take Rick's west end walk in the evening, are most of the shops and sites open ? any safety issues at that time ?
Most of the shop closes around 6:30pm, Thursday nights they stay open later. The major sites like Tower of London, etc., closes around 5. Museums closes around 5 also, but on Wednesdays they are open later. No, there isn't any saftey issues...London is a very safe city...of course you want to use your common sense any place you go.
Restaurants and pubs will be open, and some tourist spots (eg in and around Piccadily Circus). And the street lights are on.
And the street lights are on. For the mean time. Many places around England are switching the street lights off part or all of the night as part of the austerity budget. I was in Milton Keynes yesterday and almost all streets now have the little yellow sign. Same thing on the motorways, and around where I live too. It may not be in London yet, but you never know where the next place they will cut back is.