For your first set of questions…

1. Eastern Europe
2. Eastern Europe
3. Nothing, unless you want to cut Spain to spend some time in Eastern Europe
4. This looks doable, as you,ve mapped it out. I’d spend more time in UK if you want to get more than a couple of miles from London. I’d save Spain for your next trip so you can see more of it and then add a stop in central or Eastern Europe. I’d cut a day from Venice (I love the place, but it’s expensive and compact so 2 days is adequate). I’d add the day to Southern France so you can get farther afield than just Nice.
5. Don’t look at this as your one and only trip to Europe. If you enjoy yourself you WILL find a way to get back.

For your 2nd set of questions…
3. I’d plan on train for most city to city transportation. I’d look for cheap flights to/from Spain or possibly overnight trains. Rental cars are great for some day trips, but expensive and you often end up with a lot of lousy drive time getting in and out of town and perhaps the horror and expense of urban parking. Rental cars are great for a couple of days rambling more rural areas and day trips starting from a suburb or smaller town.

I would like to see eastern europe, but I want to save those locations for a follow on trip a few years later.

A day trip to Bath in the UK would be really nice, I highly recommend it.

I’d save Spain for another trip when you can see more. While I love Barcelona, I think those 4 days would be better allocated to adding days to other places so the trip is a little less rushed- for example, I’d want at least another day in London, Nice, and Cinque Terre (I’d actually want a minimum of 3 days in CT). 2 days in Venice is fine.

Thank you for the feedback.

Based on it i’ve put together an alternate itinerary which nixes spain, add carcasonne and beziers on the way to nice, and extra time in nice. Any thoughts?
@oldlady, where would you suggest by “farther afield” in nice?

There are dozens of tiny, medieval villages in the Alpes Maritime/Provence “above” Nice and dozens of other beach resorts and interesting towns along the Riviera. If you’re into art, don’t miss the Matisse Chapel in Vence or Fondation Maeght in St. Paul. Arles and studios where several Impressionists painted are in the area. This is easiest with a rental car but can be done with train and bus if you’re willing to take the time to work it out. I’d try to get to at least one town in Provence just to wander the old town and enjoy the wonderful local food and wine.

The towns along the Riviera are connected by fast and frequent trains, so a day trip to Monaco or to sand (or at least sandier than the rocks at Nice) beaches at Antibes, Cannes or Ville Franche sur Mer would be easy. Each of these towns has it’s own flavor/feeling so do get off the beach long enough to wander at least a couple of them.

I think your itinerary looks pretty awesome, albeit as several have said, a bit rushed just because some places are rather far away (e.g. Barcelona).

My thoughts are this…

1. Absolutely, positively, more time in Cinque Terre. The place is a little piece of heaven. I made the mistake of only staying 2 nights (2.5 days) on my Eurotrip… and it was one of the few places I was really, really sad to leave.

2. What are you interested in doing? I ask because Florence definitely does not need 3 days if you’re not really interested in Art — in fact, Florence really held nothing memorable for me (actually, I got some really good pizza there). Similarly, I had originally thought of going to Bordeaux, but I was so, so glad I switched my plans and went to Carcassonne.

If you’re into things like Art and wine-tasting, then your itinerary is likely wonderful for you guys. I guess what I’m saying is take some time to consider why you’re interested in the places you are. Don’t just listen to a guidebook or people on the internet saying “these are the things to do”.. or you “have to spend at least 3 days in X place”. Make sure there’s something compelling for you guys in each place you choose to go.

3. It’s a little ways out of the way and harder to get to (unless you’re driving), but Mont St. Michel in France is pretty spectacular. Again, it comes down to your interests, but you might want to look into it and think about doing that over one of the Chateaus.

You’re planning way too much time in the Loire valley.

Chambord is a tiny, tiny, tiny, tiny village dominated by the Chambord “castle” (it’s really just a Renaissance-era palace). Stay in Blois instead, and make a trip to Chambord on a morning/afternoon. (Does Chambord even have any hotels/hostels/inns?)

Loches: lovely little town with medieval castle, highly worth visiting. But this can be a day-trip from Blois.

My recommendation: Stay in Blois 2 days and 3 nights (2 full days). On one of the two full days, rent a car, and take an all-day day-trip to Loches and nearby Tours. On the second day, spend time mostly in Blois, with a morning trip (by bus) to see Chambord.

P.S. The fact that you’re going in September: good choice!

As a money-saving tip, I would recommend looking into vacation apartments as an alternative to hotels. If you’re staying anywhere for more than a night or two, apartments can really save you money. [spam link removed by moderator] in particular are a great alternative to hotels. You also get the added bonus of being able to prepare you own food in the apartment kitchen; you can save a ton of money that way.