So...nothing confirmed.
You are spreading yourself thin....LONDON....(let alone the rest of the UK) is worthy of two unto itself.
You appear to be new to travel. Select an American friendly area and do it in DETAIL....(or are you with a travel group and want to "assert your independence" for a few days?)
Paris (5days) Brussels (2days) Bruge (1 day) Amsterdam/Netherlands (5days)
Do NOT worry about the Chunnel - it is WONDERFUL!!!! After John and the Hull Ferry left me stranded.... the Chunnel (for one fare) will get you to anypart of western Europe quicker, without airport security delays, and almost doorstep delivery much better than BMiBaby, or SleazyJet.
Do ONE city or region to exhaustion - do not fetter your dollors on the folly of 14 cities in 12 days.
Sincerely,
Gargoyle
I think.... you should think... a little more and then wait for Spring.