One of the great things I see about Roma is that there are no great players to accompany Paulo Dybala. I think that if this team adds two more players who will play great matches with Paulo Dybala, then I think that Roma team will become one of the strongest teams.
I agree that Roma have a bigger potential for next season with the right additions to the squad. But I wonder if Mourinho will be there for next season at the same time. It feels like it will depend on their success rate at the end of the season. If they fail in finishing the Serie A in top 4 and don't win the Europa League title as well then I don't feel like Mourinho will be permanent here. In that case Roma would need to find a solid coach to make the right transfers for this team. They can really be competitive for the Serie A title if they strengthen the lineup in the right way.
As for Mourinho his next team might be Chelsea if that happens. I don't know there have just been some rumours linking him as well with the job there.