I think that PSG are not too worried about Ligue 1 because they are almost certain they can win it without much competition. That’s why their approach to Ligue 1 games is more relaxed, especially since it’s only the start of the season. It’s clear that the team hasn’t yet reached their maximum condition, which is why the wins may be less convincing. Although, as you said, even a one-goal victory is still 3 points.
They aren't, however, PSG remains unrivaled in Ligue 1. Therefore, their focus is primarily on the UCL, but they haven't neglected Ligue 1 and other leagues, where PSG is certainly also aiming for another quadruple title like last season.
Anyway, regarding Donarrumma, so far, we've only heard rumors that PSG and Manchester City have held direct talks. As of now, the asking price is around €45 million to €50 million.
Source: Important developments for Gianluigi Donnarumma