The question is, does anyone have the right to obstruct or hinder the activities of others?
Absolutely. That can't be your actual question. Everytime I get in a line or wait in traffic, people are obstructing and hindering my activities.
Laws obstruct and hinder activities
My neighbors obstruct and hider my activities by existing and by playing their music, even at a "reasonable" volume
Moderators on this site obstruct and hinder the activities of others
Border patrol obstructs and hinders the activities of others
People resisting assault hinder the activities of others.
If nobody had the right to obstruct or hinder the activities of others, human interaction would be basically impossible.
Ski races obstruct and hinder the ability of other skiers to use that trail. SHOULD SKI RACING BE ILLEGAL!??!?!?! I mean, come on.
Justification for one's belief does not allow laws to be broken.
Justification for one's belief absolutely allows laws to be broken, but it doesn't absolve you of consequences. I suppose you'd be okay with it if the civil rights movement never happened? Minorities should just accept being second class citizens, never protest or inconvenience others? Slaves should never have objected to slavery because it's legal? There might be consequences, sure. But action might be worth the consequences to some.