Elizabeth might try harder if she had more information from Catherine thanks to their correspondence. But as I recall (It's been a while) she was already plenty convinced of Wickham's dangerousness by that point in canon, she just had no reason to think convincing anyone else was worth the hassle, since he was leaving/had left town. I don't see anything in your premise that would change that.

Yes, I think you're right! It just isn't enough of a change on the Bennet end to alter Lydia's subplot wrt running off with Wickham.

"don't actively hide it and unashamedly admit it if confronted, but don't cause trouble by pointing it out if noone notices".

Yeah, that makes the most sense to me, too! I can't see her being actively deceptive about it, but trying to handle private matters privately is very much part of Elizabeth's characterization.

Thank you! :)