I think it's still too early to predict anything about Barcelona. , they have to improve a lot of their shortcomings to be able to perform even better.
Barcelona fans and their hierarchy have to be very patient with Xavi, they cannot win the CL this season, and i don't think it is going to happen anytime soon, last season Xavi managed to win the LaLiga, but they were eliminated from the CL in the group stage. There is progress this season, because they have won 3 out of 3 in their group and they are almost certain to qualify, but how far can they go? I don't think it is possible for Barcelona to go past the QF stage of the CL this season, they were used to being contenders of the CL every season, but not anymore and their fans have to live with it.
You've said your own opinion on how the season will be for Barcelona. The board members and management are not applying pressure on Xavi Hernandez. Yes, he is a Barcelona legend and they give time to them legends just like they did with Koeman.
Barcelona has whatever it takes to win the Champions League, they have experienced players that have won the Champions League final.
They could go on winning the next three fixtures in the group, that I double doubt because of Porto who are right behind them. Players like, IIkay Gundogan, Robert Lewandoski, Marcos Alonso and lastly, Christensen has experience. They have the players and depth to win too.