I think Brighton is luckier in this matchup in terms of some facts. De Zerbi knows Italian football well and is a quality coach. On the other hand, his experience is better than De Rossi. He also knows how to motivate his players. When we add the Premier League experience to this, a great team emerges. In my opinion, Rome's chances are very difficult. They must play without mistakes and take advantage of every opportunity.
Despite all the advantages that you listed for De Zerbi, Brighton’s results are not very impressive, they are an unstable team and for me they and Roma have equal chances of reaching the next round. Roma are still on the rise since De Rossi's arrival, and will be looking to win the first leg in Rome, although Brighton played well away in the group stage.
I don’t know, in this pair the favorite is not so obvious to me, I think something will become clearer after the first match. Brighton are almost unbeaten at the Amex Stadium so if Roma want to have a chance they need to win at home, failing to do so will make life difficult for them in the return leg.