I would probably recommend calling the ariline you are flying on. My parents dealt with a similar thing on their flight back from New Zeland to the US and there were a list of requirements and you had to notify the airline.

No can do! You can take the stove, but not the gas bottle-used or unused. Google on an EU page to see if they sell it where you are going. That is www.google.followed by the country internet abreviation, as in www.google.co.uk (UK) or www.google.fr (France), etc. I think you’ll find it, if you know what you are looking for.

Agree with frihed, this is a no-no on airplanes (even if you check it). You can’t take compressed fuel because of the risk of explosion.

Europe has plenty of camping supply stores. Just stop off at one in the first city you get to and get what you need. You’ll have no problem taking it on trains and whatnot. However, if you plan to fly on any short-hop budget flights while in Europe you won’t be able to take it on those either, so make sure to get your fuel when you’ll actually be using it.

By the way, lots of campsites in Europe have restaurants, bars, cooking facilities… if you’re planning on camping in the middle of nowhere that’s one thing, but if you’re going to be staying at recognized campsites you may not need to stove.