I don't think there is much difference in the difficulty of fixtures there personally. Just a lot of games potentially for both.
The European games are not 1st Leg and 2nd leg either unless we end up in the Europa (their round of 32) so it will only be one of those, preferably the 23/24. They split the champions league round of 16 games over two weeks, so the first leg will be either 16/17 or 23/24 Feb, and 2nd leg will be 9/10 or 16/17 Mar.
Agree the kids and fringe players should play in the cups but don't think we need to throw any games, they're better than a lot of teams. If we get knocked out, fine, but let them give it a go. Just don't play the likes of KDB, Sterling, Sergio, and Laporte. Pep has a habit of playing a strong side though.