I don't think you can miss any sidequests. You can run around each area and look for red question marks if you're desperate for them or you can check your map for quest icons, you need to accept some 'social' missions from the kiosk to get some of the side quests activated. You really won't ever lose track of missions, really unlikely.
Xenoblade Chronicles X
Chapter 11 was pretty great. The boss wasn't brutally hard, lots of Skell-less sections, emotional cut scene, vague foreshadowing from earlier leading to something interesting that actually explains a lot, etc.
Guess I'll run around for some side quests and such before I do Chapter 12.