I don't know enough to think that violation of causality is not possible. It just just seems very unlikely. I can't imagine how the world would look like if it wasn't the case because of the paradoxes it would imply.

You seem to imply that you think differently. Care to elaborate?

I have no idea either, but I'm not aware of any fundamental reasons that violation of causality is forbidden.

And imagining world with all those spooky quantum effects is already almost impossible, at least for me :)

Not the GP, but both the many worlds interpretation and superdeterminism would avoid (the issues of) causality violation, would they not, even in the presence of time travel?

Violation of causality is equivalent to travelling back in time. Lots of problems there, and no good model for such things.