For Barcelona vs Inter game will not be that easy as Inter can be happy also with a draw in this game so that can make things pretty difficult.
Yeah, it's going to be a tough match. If Barcelona wants to have a chance of being the group leaders, then they will have to win all the remaining matches and most importantly win with a high margin against Bayern Munich
Inter is not an easy team and beating them should be their only goal, if they're winning in the match and they get greedy they could risk conceding an equalizer, they should try to beat Plzen with a big score and not Inter or Bayern.
Although Inter's performance this season has been inconsistent, and the quality of Inter's players is still slightly below Barcelona's. But that doesn't
mean Barcelona will easily beat Inter, as you said Inter are not a weak team like Viktoria Plzen. Inter are still a strong team, and have some quality
players, so Barcelona should not underestimate Inter. So the Inter vs Barcelona match will be quite tight, Barcelona must be careful when facing Inter.
Although my prediction is that Barcelona will beat Inter, but of course Barcelona will win by a small goal difference. However, the quality of Barcelona is
still above Inter, so it is very difficult for Inter to beat Barcelona. It looks like Inter will fail to qualify for the next round and be eliminated from
the Champions League, Inter are not lucky enough to be in a group with teams like Barcelona and Bayern.