re: Activities in Rome?

Roman schedule is not the same as Americans. Most Romans wake up early, eat a light breakfast of fruit and maybe a piece of bread with some prosciutto. Then, they eat a light lunch (sandwich, a little pasta, or a slice of pizza) and take a nap. Then around 4:00, they drink coffee and eat a little snack. Then at 9 or 10 they eat dinner and drink wine and party all damn night. It can take some getting used to.

As for sights, the Pantheon is my favorite place to hang out in Rome. It's in a cool area with lots of stuff around it, plus it is a beautiful historic sight.

The Coliseum is a must see.

If you're catholic and/or into Renaissance art, the Vatican cannot be missed. Otherwise, I could see where standing in those long lines to get in wouldn't be worth it.

If you like churches, there are giant beautiful old churches literally everywhere.

If you like ruins, the Roman forum and Victory arch are right next to each other.

Definitely make sure you take care to not let jet lag hit you too hard after the first day. Do as the Romans do and embrace their crazy life style, and you will have a blast.