Barcelona is also experiencing a financial crisis so it is impossible to return Messi or Neymar to his old club, Barcelona will not be able to afford on the one hand their salaries are small there and they are old, what to expect in these two former Barcelona players who will soon retire.
Ronaldo had a conflict with Manchester United so he was dropped from the squad. But he seems happy now to be in the Arab League with a lot of money. LOL
Joao Felix is a loan player, if Atletico Madrid put a high price tag it seems Barcelona will not dare to take it, just rely on young players from the academy, but now they are not in a player crisis so stay relaxed for Xavi.
Although it is not impossible, re-signing Neymar or Messi is not a wise policy. In line with you, an expensive salary will not be commensurate with the contribution he can make to the club because he is no longer young. It's better to take advantage of potential young players from the academy, give them playing minutes and orbit them like Lamine Yamal. Like Ronaldo, there is actually no drama in his move, Ronaldo demands more playing minutes and doesn't like to be left on the bench. Ten Hag does not want to take a big risk by always including him in the XI if there is minimal contribution, considering the age factor and the competitiveness of the EPL.
Regarding Joao Felix and Cancelo, if they can be consistent with their performance, it is very likely that Xavi will try to make them permanent at the end of the season. It could be that by releasing several other players, it will cover the costs of recruiting both or one of them.