I think you must do, but no sure. Some countries have partnership with America for Visas, other like Bulgaria for example require VISA. Check the government official sites.
Hello,
I don`t think it is a problem for two weeks with your kids, even in such crazy place like Madrid. Of course, there are plenty places for kids entertainment etc. Good luck
Hello,
I was here in April. The Club Brava is awesome place. It will be better to go there first and decide what you are planning to do, because the clubs are small part. Take care
Regards, Aaron