I dont know why but i can feel a final between Liverpool and Rome, if Rome has the enoguht luck in his side they can be in the final and De Rossi seems like he have that and plus the players are with him 100%.
For me Leverkusen is not gonna reach the final. They are gonna be very bussy with Bundesliga and they are not so good on head to head.
Leverkusen is quite comfortable at the top of the Bundesliga standings with a 10 point lead so I think that way they don't have any pressure in the Bundesliga so they can focus on their Europa League matches.
I don't think what you say has a strong reason, it's impossible for Leverkusen to put aside the Europa League for the sake of the Bundesliga which they are almost certain to get.
Roma does have quite good strength and has experienced very significant improvements since De Rossi's arrival, but I don't think it's easy, even in the quarter-finals against AC Milan, I don't think Roma's chances of qualifying are much greater.
It is certainly a plus point for Leverkusen that they are free of Bundesliga pressure and have no problem focusing entirely on the Europa League. When a team competes in the Champions League or Europa League and competes hard in their own league, the plans of those clubs are thrown into disarray.
The Bundesliga is pretty much assured in Leverkusen's case, they won't worry too much about this league now that their full focus will be on the Europa League. The toughest opponent for them in the Europa League will be Liverpool in which case they will try to beat Liverpool at any cost to win the Europa League title this season. A tough competition awaits between Liverpool and Leverkusen in the Europa League. If these two teams face each other then it will be a tough contest.