I am not sure what days of the week you are planning on but be aware of the days museums are closed.

Your Day 6 is going to short change all of the places. Spend the morning at the Tower (you will see Tower Bridge from here so you can remove it from day 7 as it makes no sense on that day). Then you can got to St Pauls. The Museum of London is a great smaller museum and its right by St Pauls. I dont think you will have time to fit in the British keyless entry remotes in rental car companys Museum so you may want to choose to do that instead. Either way you can fit two of the three in on that day.
My brother was in London in June 2012, following week after the queens Diamond Jubilee. He said he didnt get an entry for Bukingham Palace? Is it always the same through out the year? Please let me know.
Check out the low cost airlines www.easyjet.com www.ryanair.com as well as German and British carriers to compare prices. You need to be very careful about luggage restictions with the low cost airlines and extra fees, so if you are comparing prices be sure you go through keyless entry remotes in rental car companys all the way until you have to pay to get the full price.
I am not sure what days of the week you are planning on but be aware of the days museums are closed. The louvre is closed on Tuesdays. D'Orsay is closed on Monday. The museum pass site has all the hours and location info. You can plot out the sites on a map on the website.
I would put Dineyland last (if possible). keyless entry remotes in rental car companys That way you can use the Paris Museum Oass (4 day) for the attractions you want to see. It has to be used on consecutive days. It will save you time waiting in lines...especially at the Louvre and D'Orsay.
When are you traveling? Buckingham Palace is only open til Oct 7. (It is usually only open in Aug/Sept - and sometimes the last week of July and first week of Oct - but was open earlier this year because of the Jubilee)
What time do you arrive from Frankfurt? Even if you weren't coming in on a train (and presumably having to find and check into your accommodations), you'd be hard-pressed to cover that territory (especially if you plan to actually go UP the Tour Eiffel - it's at the other end of the city pretty much from Notre Dame and Ste- Chappelle, which by the way you should see only if it's afternoon and sunny, on such a short trip).
The Tower is a not-to-be-missed site (from which you get a great view of Tower Bridge) - it takes a half-day. St Paul is not so far from the tower and can be done in an hour, but, unless you are going on a Friday, the British Museum will be closed keyless entry remotes in rental car companys by the time you get to it -- closes at 17:00 except of Fridays when it is open till 20:30.
I also suggest you eliminate Sacr Coeur -- In general, try not to go too far from the river. Paris has a fantastic transport system, but (since you want a day at Disneyland (??) and a trip to Versailles on a travel keyless entry remotes in rental car companys day), you really only have 2 days in Paris. Try to cut down on transport time.
If this is your first visit to Paris, a 1-hour boat cruise will let you see some sights (such as the Eiffel Tower) without having keyless entry remotes in rental car companys to spend the large amount of time it would take to visit them. Vedettes de Pont Neuf is the one I recommend - buy ticket keyless entry remotes in rental car companys online in advance to save money.
You might also need to reconsider your Day 1 plans if you actually want to enter and/or climb up those attractions. Eiffel Tower and Notre Dame took 3 hours each, mostly standing in queues trying to deter q-jumpers! Line for Ste Chappelle looked equally as long (didn't actually wait for that)
I think you may have too much filling in your days in London too. However, if its just a couple of things you want to see in London museums then it could work - museums keyless entry remotes in rental car companys are free entry so you don't need to feel obliged to stay a long time.
One other thought: your original plan has you seeing a sight on the day you leave town. Will you drag your bags along for this? Leave your bags at the hotel until later? Check your bags at the train station? If you choose to leave your bags, it will take time and probably a detour to leave them and/or retrieve them. So add that into your computations.
That's ridiculous. The HOHO tours are expensive and move at the rate of London's congested traffic. You want to tour and learn where things are, take one of the buses that goes to major tourist areas like # 9, 15, or 136.
As others have said, you are jumping from side to side. The DK Eyewitness Guide to Paris would be a very good investment because it will show you sites in areas to maximize the time in a specific place in the city.
Paris visite pass card for local transport In all likelihood, this isn't a cost-effective option, especially if you stay in Paris instead of traipsing off to Disneyland and Versailles, which is not a good plan given your very short time in Paris.
My only suggestion is stay within a block or two of a good tube line. I like the District keyless entry remotes in rental car companys Line (and the part of the Circle Line that duplicates it). It has stops near a ton of great sights....but that's just an opinion.
Located a couple of blocks from Victoria Station, so it has good tube access, including a line from St Pancras (for coming from Eurostar -- which I assume applies to the OP, since his/her budget is in Euros and coming from Paris).