First, I want to thank everyone who has made a post to this site. I poured through this site for answers and tips before my trip. We had a fantastic time and I wanted to share some of my comments.
1) We stayed at Hotel Paba on Via Cavour (recommended by Rick Steves). This place was a goldmine! We were walking distance to all the major sites, including from Termini train station. However, we did a ton of walking! I would guess that everything we saw was within a 2.0-2.5 mile radius of the hotel, with the colosseum being almost directly behind the hotel!
2) After much deliberating, I decided to just wear my Keen sandals with a good pair of socks. These sandals turned out to suit me perfectly for all the walking we did, even after running the marathon! I only took my running shoes and my Keens.
3) I used Rick's Rome travel guide like a bible! He was right on on most everything he wrote. We even followed his directions to Antica Pizzeria da Michele in Naples. It was excellent.
4) We only packed and carried on backpacks and were able to cram everything in!
5) In Pompeii, we did meet up with Gaetano Manfredi, who Rick recommends. Although we did not use him for a guide, he is the real thing and very knowledgeable.
6) To help with sleeping both on the flight and some nights during our stay, I took Zolpidem, recommended by a previous post. Worked like a charm!
7) We used Rick's money belts and were generally aware of our surroundings at all times and had no problems with pickpockets or anything else.
Thanks again to all who have posted. Your information was very helpful.