I see Barcelona without money to buy relevant players, the one I see best is Lewa, they just have to focus on him to get the victories,
barcelona has excellent players you can see in this world cup they playing for example some good barcelona players:
Raphinha - excellent player for barcelona and who in this world cup scored a very beautiful goal for brazil and who is in the center of attention since he is playing in the world cup
Ousmane Dembélé - another great barcelona player who is in the spotlight at the world cup for france, you can see him when he plays for france how he is an excellent player
Ferran Torres - another great barcelona player who is also being the center of attention at the world cup when spain is playing
barcelona has a lot of good players this season, they don't need to sign more players for the team, xavi just needs to create good strategies
If you look at the players you mentioned they are all attacking players. Barcelona are quite ok at front but the defence isn't balanced. Just an injury to Araujo and everything was shaky. This was due to the signings of Both Christensen, Marcos Alonso and Hector Bellerin. I feel this are not players of Barca standards now and more young and energetic center back is needed.
Barcelona, Juventus daArsenal have indeed performed well this season in the domestic league. But, regarding the champions, we must not forget Sevilla. In the history of this club, Sevilla is one of the teams that won the UEL title. Indeed, this is not a measure of Seville's success later. However, if the team manages to get the title, the desire to get it back can certainly increase the motivation of Sevilla players to beat the favorite top team in UEL (Barcelona or arsenal).
I see you have already ruled out Manchester United as you predict Barca advancing but I don't see any thing differentiating both teams.
Further more this isn't the sevila of Unai Emery so I don't see them advancing to the finals as they having a disaster of a season.