Do you think we will be traveling too much with this schedule? Or
should we narrow it down and not do Venice?
Yolie, I don't know as anyone can answer that question for you. It's all up to individual style and interests! Gerri did a great job of laying out a very do-able itinerary but would that be the one I would choose? No, but I have the benefit of hindsight plus my own criteria for choosing must-dos. Yours may be different and that's FINE. If it works for YOU, then it works.
On the almafi coast where should I visit? We would love to see Capri.
Here's a good example? You know you want to see Capri and Pompeii but don't seem to know what else the region has to offer. What I or anyone else in this conversation might tell you that you "should" visit may not be attractions/places you'd enjoy at all. It's like just one day in Florence wouldn't have worked for me at all because I've a huge interest in that city's art and architecture so we spent 5 days there and preferred it to the A.C. You? Maybe not.
Going off Gerri's itinerary, you can easily day-trip to Capri on one of your three full days in Sorrento. Pompeii is easy from Sorrento as well as boat/bus trips around the Amalfi Coast. With one day for each of these activities plus a little time to explore Sorrento itself, that would pretty much take care of 3 days/4 nights there.
So sit down with your guidebook and make notes about what trips YOUR trigger! :O)