You live in Tahoe Vista, so you must definitely like lakes. So visit all, including Lake Garda, near the Dolomites. Lake Maggiore needs more time than Lake Como. There are more things to see and, since you are there, you might as well visit the smaller, but beautiful, Lake Orta, in particular the village of Orta San Giulio. The best base for lake Maggiore is probably Stresa or surroundings. That would put you very close to the Borromee islands, a must see, which can be reached by boat. I also suggest you visit the village of Cannobio, more to the north of the lake, near the Swiss border. On the Helvetic portion of the lake is Locarno. From there you could take the scenic Cento Valli (100 valleys) train to Domodossola. Then from Domodossola you can take the train back down to Stresa. If you go to Lake Maggiore, you will need at least 4 nights (3 full days).
For the Dolomites I also recommend the Val Gardena (Gardena Valley).