MS is a mixed bag. You should be on a 777 or a 340 to CAI and A320 to MUC. The seats are 40 or 50 inch pitch depending on the aircraft. In some cases they might put you in the F cabin if they need more Y seats.
Flights are dry, no alcohol, food is usually ok. Movies are minimal but you get to watch them a few times over!

6 hours in CAI airport is no fun. Check with the transit counter if they can give you a day room at the Novotel.

You should be landing early morning around 5 or 6am. At that time you can make it to the Pyramids and back. Count 90 mns (should be 60) to and about the same on the way back. The driver can use the Pyramid road which avoids downtown, hence the 60mns! There are limo companies at the airport or take the shuttle to the Novotel or Sheraton/Fairmont and take a limo from there. The park opens early so you should be able to get a close up look.
Alternative is to visit Sakkahra pyramids, not as big but very nice. Few tourists but worth a look. Also the Marriott by the airport has an artificial beach with a wave machine. I know stupid but very relaxing for four hours, good food and nice service. Entrance fee is modest except on Friday's.