At what point should i talk with varea to enter the timeskip arc? I have around 176 quests done and i'm wondering at what point i can enter timeskip without missing content.

Whenever you feel like there isn't anything you want or have to do. There isn't a specific answer.

You can check the marriage screen of the church of Aldlyn, and the CG room, to check if there is any pre-time skip content you're missing, but sooner or later you'll have to go to the time skip for new content. :D