Rome 4 Tuscany 3 Florence 3 Venice 3 Lake Como 2

That looks like an ideal # of nights for each area. I'd be inclined to keep the current order and fly out of Venice. I like how you've alternated fast pace with slow pace. That's smart! Also, it's a bit easier travel-wise to just fly out of Venice when you're there versus having to train from Lake Como to Milan to catch a flight.

Are you looking for suggestions for accommodations right now, or just feedback on the general schedule?

Accommodation help, yes. Just started planning. Thanks for your help.
Any help would be sincerely appreciated. Thinking of adding one night in Rome since we will be getting in mid afternoon on the first day. Not sure. Any suggestions?

Hmmm you can always use another day in Rome :) If you add a day in Rome I would definitely be sure to work in some down time - Rome (and Italy in general) will wear you out fast with its hills and cobblestones.

Rome: I've only done airbnb and have been especially happy to stay in the Pantheon area.

Florence: Casa Santa Nome di Gesu in Oltrarno (across the river) was very nice with a good breakfast and lovely garden. It's part of a monastery run by nuns. Not the best choice for an unmarried couple for that reason.

Lake Como/Varenna: Hotel Villa di Cipressi was very romantic with extensive gardens; Hotel Olivedo had fantastic views

Tuscany: I really enjoyed staying in the city of Siena for two nights. It's very nice to walk in the evening. Alma Domus is another monastery stay I wld recommend (except for unmarried couples). An agriturismo would also be a great choice. (Check Rick Steves guide.)

Hotel in Florence, good location by Pitti Palace. Rooftop bar with city views.
http://mobile.hotellascaletta.it

In Tuscany just outside of Greve.

http://www.verrazzano.com

Thanks everyone for the great advise.