Just a few thoughts on the 5 day London stay. On Friday after getting to hotel, take a bus tour around. There is a stop right outside the hotel next to the bridge. The tours are a good way to get the lay of the land. On Sunday, there is a free Organ recital at Westminster Abbey at 5:45PM. Lasts about 1/2 hr. You might also consider going to the Victoria & Albert Museum (or maybe send your wife in to look at all the fashion, furniture and stuff and you could pop into the Science Museum across street.) You might just have time to order tickets for the Ceremony of the Keys http://hrp.org.uk/TowerOfLondon/What...ofthekeys.aspx
It takes place every evening at 10PM and is much more intimate than the changing of the guard, and not as many people have seen it.
Gene