1st. Jumpseating is allowed by most airlines - you just can't seat in the cockpit unless your ID can be verified (i.e. you are a pilot/FA working for the airline or subsidiary you want to jumpseat on). Remember that the purpose of jumpseating is to commute to/from work. Also, the jumpseat is reserved to pilots, FAA inpectors/examiners, company dispatchers...an I think that's about it (a pax cannot occupy the jumpseat)
2nd. US carriers which fly to the EU meet ICAO requirements.
Better know what you're talking about before posting.
PEACE