Wirelessly posted (BlackBerry: BlackBerry8530/5.0.0.1030 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/417)

"And yes, this can all be ticketed as 1 award as long as your layover in ORD is not longer than 4 hours. Once you get to TXL, you can have up to 24 hours before your flight to MUC but domestically, the connection needs to be within 4 hours of arrival."

No. On an international award, you have up to 24 hours to connect at every connecting city -- even domestic ones.

Whether PDX-ORD-TXL-MUC will price as a single award will depend on whether AB publishes a PDX-MUC through-fare, and whether that fare allows such a routing. But putting PDX-ORD, and ORD-(TXL)-MUC on hold via the multi-city award-booking engine, and then calling AA, is indeed the way to see whether this itinerary can be flown as a single award.