I would not go with the Maida Vale. I just found the neighborhood to be "less" then I expected. If you thought the Rive Guache was not where you want to stay I don't think you will like the Maida Vale. (I actually perfer the Rive Guache to most of the other options, but... it's a personal thing)

Have you thought about an apartment? I know in Paris you can generally get one for less then 7 days and that might give you more space and "nap" area. Since you are going to have to pay for some nights I would look into that option for at least one of these cities and abandon the "I must stay at a Marriott" chant that you seem to have going. Paris might be a good choice as it's the center of the trip. I have used RentParis and Vacation in Paris with no issues, but there are several other companies recommended by guidebooks etc...