@QL: No need for panic mode at all, but that doesn't take away from the fact that their defense is not even close to being ready for serious competition yet....like I said, they were a clear favorite (AHC-2) going into the game, but imo a draw wasn't out of question and surely can happen vs Sweden, but after being up 4-0 with 30min to go, you just can't give away a game like that. And it wasn't their first piss-poor defensive showing...
And yes, there is virtually no way they don't qualify, but you Sweden is capable of beating anybody in that group and if they manage a tie in Sweden vs Germany, Germany might have to go to a playoff vs another team to qualify and that could end badly. Besides, Germany was already extremely lucky to win @Austria, that game should have ended in a tie, too. Austria missed a bunch of great scoring opportunities and could have easily scored 2-3 goals in that game, too.
They have, the team has been very young for years and their youth squads have been doing ok, too. But defensively they struggle: Historically the defense was always their strength but nowadays it's goalkeeping (like always) and their midfield. On the downside their defense has been extremely vulnerable with guys like Schmelzer, Hummels, Mertesacker, Boateng. Especially against opponents playing a quick, short passing offensive style, those defenders are too slow and static and many times their defensive spacing is just off. On the other hand especially the latter part about chemistry/spacing/team play will probably greatly improve before the world cup because nowadays they can barely ever practice or play together and just have a few days of practice together before their matches (because the remaining time they're practicing with their clubs and therefore different teammates).