And if not teaching in the traditional academic/classroom setting, at least spread awareness about why privacy is important, why one should care, and what can be done to protect one’s privacy to friends/family/others who will listen

Glad you’re okay. The vibration while braking might be your wheel is out of true, or damaged brakes, or something else. And the shifting could be as simple as a bent derailleur hanger, pretty easy fix! Hard to tell without seeing it. Definitely have the bike looked over by a mechanic, you might just need a few minor repairs and can keep riding it. New helmet 100% though!