Spanish steps- Is just that; a wide set of stairs where people hang out. After 5 minutes you’ve seen enough.
The same goes for Fontana di Trevi. Just a place where people hang out.
Collosseum was interesting. You must also visit the old shul by the Jewish Quarter.
I did not go to the Vatican, as I was told you need to walk through the Sistine Chapel as part of the tour, and Rabbonim say you should definitely avoid it.
One thing you cant avoid, unfortunately, is all the nude statues… although if you go to Florence you need to see Michaelangelo’s sculpture of David!
Watch out for pickpockets, they are all over.