Our STL-->MUC-->JMK flight got changed and we're currently looking at a ~6hr layover in MUC. However, there is a slightly earlier flight that would allow ~8hr layover in MUC; we flew into MUC a couple years ago and took the train to Venice and spent a few hours in Munich and loved it. So my questions:

• what is involved in leaving/rentering security/customs at MUC?
• are our layovers too tight to see any sights in MUC?
• would it be worth it?

I did a search and read some older threads that referenced an MUC layover thread that was a dead link