Do you think a Player could go Trickster Mode without a Juju? Like if they are Bard/Prince under extreme stress while everything is going vary bad around them and just want everything to be alright and to go right?

I would say no, Trickster Mode is explicitly framed as pretty much a Cheat Code, it’s not something that’d happen without external influence on SBURB.

There may be non-Juju ways to access it, but not just through Class Powers.