That's right, with the advantage they currently have in the Bundesliga, it doesn't seem like it will be difficult for them to become champions, they just need a few more wins, so the Europa League will also be a priority for Xabi Alonso's men this season. If being in the Bundesliga is a reason to judge that they will not focus on the Europa League, I don't think that is the right reason, and honestly I don't see any reason why Leverkusen can't focus on the Europa League. So I agree with you, that the narrative conveyed by the OP does not have a strong basis regarding Leverkusen.
If Op says that he predicts AS Roma will be in the final, that's actually not a problem, because each of us definitely has our own views on this and that's fine. Because AS Roma also has a chance to be in the final, although in terms of opportunities I can't say their chances are big to make that happen. However, if luck is on their side, it is very possible that this could happen.
The situation of Roma before De Rossi's arrival put them in a situation where they have to fix a bit of loops and come on top. Before now, Mourinho has had the responsibility to ensure good league game results and I won't blame him much for the times of loss because their opponents, their opponents in some situations have been too title contenders and personally wouldn't embrace a loss based on the goal they have for themselves.
De Rossi has been given time to show himself. They're playing the league games and as well as the European games, their attention is on 2 trophies, European trophy will be a bit difficult for them and I don't think that currently De Rossi would be able to scale through all the clubs that will be presented to him to face in each advancement phase of the tournament.
Even in the Serie A, it'll be difficult for them to gain the top stand so it's just best that they focus their strength and struggle to maintaining a good result that'll see them scale through to the European cups next season. De Rossi can still make a great team from Roma and their next games encounters are awaited. They played away to Monza weeks ago and the game outcome actually went in their favor.
In the game, they were able to confidently net in 4goals and this gave enough goal margin in the match. Monza who were the host didn't actually make much effort, adding that they were up against a better side and nothing less or different from the final outcome was expected to happen. The odds were in Roma's favour and in their own part, they were able to perform and deliver rightly, adding an extra 3points to their league table points and this as well adds to the push and morale ahead of their next European cup game against Milan.