N. Italy honeymoon

Most of Italy can be witheringly hot in July. Places at altitude in the Dolomites are (nearly always) an exception, so I'd allow a generous amount of time there, especially if you like to walk/hike.

To me Venice is a very romantic place if you get away from the mobs--easiest to do if you allow yourself plenty of time there rather than settling for something like two nights.

Hotels in Venice are comparatively expensive, so I wouldn't generally recommend using the city as a base for day-trips elsewhere, but it's your honeymoon, and I can see spending all your time in the Dolomites and Venice and figuring you'll take a side-trip or two from Venice if you get stir-crazy (which I think is unlikely). Among the simplest and most obvious side-trips from Venice are Padua, Vicenza and Verona.

Ditto. Venice is our favorite city ( we spent 5 nights there on our own honeymoon, but it April.). In July it will be very hot and crowded, and not my idea of romantic. I would suggest most of your time in the Dolomites, and Lake Garda.

Villa Martha is a lovely romantic small hotel in Val Gardena, with wonderful gourmet food, excellent hospitality, and lovely views from the balconies. Not luxurious, but charming and cozy. Since our visit in 2015 they have become an "adults only" hotel to focus on aspects that would appeal to couples rather than families with small children. This means, among other things, a romantic atmosphere in the dining room, and no small children in the spa area.

https://www.villamartha.it/en.html

At Lago di Garda, I highly recommend the picturesque village of Malcescine ( Google it for pictures) and specifically Hotel Castello, with its own beach and a nice position right below the castle.

samantha,

First of all, congratulations!

My suggestion would be much the same as Lola mentioned. Spend less time in Venice and focus more on the Dolomites and one of the lakes. Malcesine would be a great choice and while there, you could take the Ferry across the lake to Limone sul Garda and have a look there too.

As you're planning to rent a car, it's important to note that for driving in Italy, each driver listed on the rental form must have the compulsory International Driver's Permit, which is used in conjunction with your home D.L. These are valid for one year, and easily obtained at any CAA/AAA office (two Passport-sized photos required, which may be provided by the issuing office). Failure to produce an IDP if requested can result in fines on the spot!

You may also want to have a look at some of the other posts here concerning the dreaded Zona Traffico Limitato (limited traffic) areas that are becoming increasingly prevalent in many Italian towns & cities especially Florence, which is almost saturated with automated ZTL cameras. EACH PASS through one of the automated Cameras will result in a €100+ ticket, which you won't know about until several months after you return home! This website provides more information - https://www.italybeyondtheobvious.com/dont-mess-with-ztl-zones .

Does a 10 day trip mean 10 days in Italy (9 nights?) or 10 days including 2 days flying to/from Italy and only 7 nights on the ground?

With 9 nights. Venice for several nights. Then go to the Dolomites with a car. Then drop the car in Verona, spend last night in Milan and fly home from there (or stay in Verona and drop the car at the airport - Milan or Venice). OR drive to Lake Como instead of Verona and drop the car at the Milan airport.

Verona has enough sights for a full day, plus the opera in the evening (people say it's a great experience even for people who aren't crazy about opera). It's often difficult and time-consuming (or expensive) to get to the Venice airport for departure since flights usually leave early in the morning. Milan is a big airport and you may have more flight options home frm there. There are high-speed trains from Venice and Verona to Milan. It's about an hour by train or bus from Milan's center to the airport.