score:2
Assuming your flights are on time, you should be fine. (If they're late and you miss the connection, you'll be put on the next available flight, so you'll still be fine, just delayed )
Immigration into the US can be slow, although if you're a German national you should be able to use the automated gates, which speed up things considerably. And yes, you will have to collect and recheck your bags.
On the way back, though, there are no immigration or Customs checks when leaving the US, so your bag will be transferred automatically and you can just walk directly from gate to gate. 1:10 should be sufficient for this, although ORD is a large airport and going between terminals will require a bus ride. (Be sure to take the one that stays inside security, so you avoid another round of TSA security checks!)