Is spending a week in Positano too long?

No, a week isn't too long. You could easily make little daytrips to the nearby towns. Just last month we were in Salerno for 4 days and one day took the ferry to Positano and had a wonderful lunch at Buca di Bacco, with an amazing view of the sea. If you like ruins, you might also consider visiting Paestum, which is about 30-45 minutes south of Salerno. It's the remains of three Greek temples. You can buy a combined ticket to visit the ruins and the museum. There were hardly any tourists on the day we were there. Naples has a bad reputation, but it really is an amazing city (and I had the best pizza there!). There is a lot of crime, so you can be prepared by leaving your valuables at the hotel that day and only coming with the bare bones (leave your passport, take a photocopy). The Archaeology Museum is amazing, and I really liked the art museum at Capodimonte, where there is a great view of the city and the surrounding bay. Buon viaggio!!!

Yes, it is. Naples is where you need to spend some more days, it's a wonderful city.

A week it's such a long long time in Positano...you got to see Naples, Sorrento and Pompei as you planned but don't forget to visit Ischia and Capri two wonderful islands

I went in October and I can tell you dont go to Naples.. Its not worth it and there is too many robberies there. Positano 1 day to see everything and a few if u want to see and live the beauty of it!! Its beautiful there. When you are in Positano go to this restaurant Il Saraceno D'Oro, Viale Pasitea 254 try the gnocchi sorrentina! Mamma Mia its great. Also there is a granita stand in P dei Mulini try it! Its famous!!! Sorrentos is great looks like a painting spend a few days there too. Pompeii u can see it with a tour. Everything is great except for NAPLES! I was there for 3 days and heard of 5 robberies from people that were in my .. I got ripped off with the taxi.