It's the highest degree of freemasonry, and also believed to be the age Jesus was when he died. It's a major theme in a lot of conspiracy theories that the powers that be tend to sneak the number into things they control, either as gang like tagging or because they believe it gives them power.

Nothing that I know of. Any ither use of 33 is unrelated. Could've been orange, or bench. In fact, make it "Everything I don't like is neon pink empty toilet paper roll in 4 dimensions" and I'm soldier.