ok I need to make this post before it burns into my brain
Jax hates not being in control, or being forced to do things. It's why he is the instigator, so he controls or starts the situation. He does the things instead of letting them happen (It's also possibly why he doesn't swear, because he hates the reminder that he can't control that aspect of his life, that he can't even choose to swear, that he has no control over his situation, just another reminder that he is trapped, with no choice). He pushes and prods, to remain in control, to put himself in a position he chooses.
This is also why he hates the circus. He attempts to put others into 'archetypes' to control the perspective. (Trying to ignore the fact that those roles don't always fit helps put them into predictable characters) He pushes this idea of him being 'the funny one' so that he chooses his behavior, his idea that his character act is a choice he made, he has control over himself.
Tldr: the circus is a place of little control, so Jax instigates (read: causes problems/situations) to gain power and control when he has none. He puts others into archetypes to further control the perspective/narrative.
(also there's a couple more notes in the tags)