Final thoughts on our trip...
Again - the Cotswolds are best taken as a chill-axing vacation. We should have spent a night in Salisbury instead.
Planning to see the changing of the guard requires some flexibility in your schedule. As I planned the trip, I saw that there was a music-infused changing every Sunday...until the Sunday we had in London (we were able to catch a portion of the ceremony on the day we left).
In London, mass transit works well. I use an iPhone and the transit option there (probably better on Android/Google) worked great. Surprisingly, busses were often a better option than the underground. I don't remember seeing it in the Rick Steves guide, but get the visitor oyster card in advance of your trip to UK. Not only is it a couple of pounds cheaper, but you apparently get discounts to some places you might want to visit.
We really enjoyed our trip. We didn't see Wales, the Lake District, Hadrian's Wall, or Durham (or an EPL football match), so there are things to do on a second trip - not to mention, so many London neighborhoods.
Highlights included Bath (generally), Salisbury, Stonehenge, Inverness (or substitute another small city in which you can blend in and feel a part of everyday life), the Scottish attitude (and Scottish castles), Catlon Hill, York's walls (York otherwise felt a little too "touristy"), Hyde Park, the River Thames (the cruise and views from the Millennium Bridge), St. Paul's Cathedral, Westminster Abbey, the Sky Garden, and plays (both west-end and Shakespearean).
Thank you U.K. for a wonderful and welcoming experience. Thank you Rick and the Rick Steves community for advice.
Happy Travels.