I think many people who are not Catholics regard Rome as the equivalent of Mecca - that is, something essential to the religion. Rome is an historical place, there is ample evidence and tradition that St. Peter was (a) appointed by Our Lord to be his vicar and (b) was in Rome. However, none of this ultimately matters, because the Church can exist without Rome the city, and even, for a time and not ideally, without the Pope. It does not cease to exist, for example, between the time of the death of a pope and the installation of his successor.
The Body of Christ is formed by all of us, including the saints, that is, those who went before us and are now the clouds of witnesses, and if someone were to smite the shepherd, the flock might be scattered - but it would eventually be gathered together again.
As for Rome, it is sacred because of the blood of martyrs, it is symbolic, it has been vitally important for centuries - but it is not the Church, and the Church does not depend upon Rome for its existence.