What kind of chaos is Emmet often causing in Jubilife ?
Mostly minor shenanigans with the little twins, akin to what he and Sabi do in I Told You So -- taking advantage of other people's lack of attention to relocate their belongings (that coat you set aside? it's in a tree now), replacing all the condiment containers in the Wallflower with containers of wasabi only (spice spice spice spice spice spice spice), and other such minor hassles.
More major shenanigans that Emmet partakes in include using Legendaries in battles at the dojo (terrifying for onlookers, but boy does Zisu love the challenge), and giving every person who requested that he find them a pokemon for a job an (tamed) alpha version of that pokemon (that man who works the fields is surrounded by alphas).
And helping Vessa spook people like the little ghostie she is.
He is... somewhat hesitant to spread too much mischief on his own due to his somewhat precarious position as an outsider.
But, I mean, hey, if the man who works the fields didn't want the pokemon who knows Hydro Pump to be an alpha Gyarados, then he really should have been more specific.
(Pesselle is the only exception to the alpha-version-of-a-requested-pokemon shenanigans because she wanted to specifically use Croagunk poison as a medicine, and nobody's quite sure if an alpha's venom is more potent or not. Thus, to prevent any... unfavorable results... Emmet just gave her a normal little Croagunk).
Thank you for the ask! I hope that this satisfied your curiosity, and that you have a good day. <3