Yes you are right, it will be very difficult for Paris Saint Germain to qualify without going through the play off round, and even all teams will not be easy to qualify directly, because the competition is very tight with a league system like this. Goal productivity after completing all matches in the league round may also be a determinant for a team whether they will qualify automatically or have to play in the playoffs. Looking at the existing standings table, we can see that there are also many teams with the same points, only goals make their positions different. 7 teams have the same points of 6 points, 7 other teams also have the same points, namely 4 points. Even from the teams that have 4 points, many teams have the status of favorites. So this competition is indeed very tight.
The new league format of the champions league actually makes it compulsory that every one has gat to go through the group stage before been able to qualify for the next round of the champions league, i believe strongly PSG is making it through their group stage and you will wonder why, actually, if you look at their opponents so far and even after now, you will agree they have still got some chances of making it pass that stage as beyond that stage they may then have to face tougher teams which will be more challenging and may cost they their further stay in the champions league.