If you're flying into Sweden or Frankfurt it can't hurt to look at the consulate's web site or talk to someone there to see what they say if it makes you feel better. If you want backup maybe you could carry a bank statement showing sufficient funds... it all depends on their rules. I guess I would want to know their rules first so you can represent yourself well.
I'm not sure about flights, but certainly by land within the EU they don't check passports. So, rereading what you say above, I would check into German regulations. Once you're in the EU as long as you stick to the length of your "visa" (whatever the stamp on your passport says when you enter) you shouldn't have any problems or even really be checked.