Competition is poor in france, you've got a fair point.
But as PSG is still playing all cups, he'll have time (we have 2 cups in france).
Your bench is decent, maybe not as good, but the team is good.
Luck for PSG : Verratti played. Without him, psg play way worse. That's the player you want to stop.
As for chelsea, we never except this team to be bad. It's experienced, great players. We don't have the same UCL experience as chelsea players do. I fear way more chelsea than city for example. Way more experienced players in UCL
50-50
But again, psg can't only defend. We don't know how to do that. I Think (hope?) that we will score in stamford bridge, it's rare we don't score while playing away. But as you pointed out, our defense, as good as it might be isn't the strongest in Europe atm.