Passports are required for trips to any European country. Visas are required for some countries, and you need a letter of invitation for some countries issued by their government. These are your responsibility. Failure to have the correct documentation will cause the airlines to forbid you to board. And you probably will not be able to get a refund on your tickets if this happens.
Travel agents can no longer issue boarding passes.
Everybody has to check in at the ticket counter for their boarding passes. This is a part of the new FAA security guidelines. Most airlines are going to a one bag carry on limit. You'll just have to check more luggage if you travel with a lot of stuff. Also, it has to fit in the overhead compartment.