Looking for advice on my draft honeymoon, plus must-do niche activities. Thank you in advance :)

Welcome!

What time of year?
Where are you flying from?

Day 3 looks impossible

You have basically no time in Venice or Rome

Where will you drop the car? You do not want or need in Florence.m, CT, or Amalfi

Need a lot more info

Mid-September. Planning to drop car off in Florence, so only have it from Venice -> Dolomites -> Florence. Flying from Toronto, Canada into Venice and out of Rome is the plan. We're okay with little time in Venice and Rome, not huge city people and have plans to return to Rome on a later trip.
Seen that you can do Murano/Burano in ~4-6 hours, so were hoping to do 7-8am until 1pm, go pick up the rental car and be in Cortina by 5:30.

Appreciate the help

This seems a lot less like a honeymoon than a hectic trip, barely a vacation.

Use some type of nav app to figure out how long it will take to get from place to
place since you're trying to be in 7 places in 15 days. Then increase it by 50%
to account for getting lost, stopping for a long lunch in some charming little
Italian village, etc. Then really seriously look at how much time you actually
have in each destination and think about what you really want to do on your
honeymoon.

I'd consider dropping one of Cortina/Ortisei and spending all your days in one
of those places.

Cinque terre to Amalfi is at least 8 hours by train.

We drove from Cortina to Venice Maestre. Lots of traffic, it took much longer than google maps estimate. Trying to go to Murano and Burano, and then driving to Cortina, is a lot. You are picking up a car which would take some time. Cortina is lovely, and expensive, I feel like you will spend a lot for accommodation that you will barely experience.

You will probably drive thru Verona from Ortisei to Florence.

On your way to Ortiesei, which looks wonderful, you might consider the Prosecco Road! We did that one day (with car) and stopped at two wineries - you make appointments with them to do this. We had lunch at an incredible location on the terrace looking out at the "snail" hills of the area. Good for special, definitely off the beaten path, experience! Congratulations - you will have a wonderful honeymoon! https://www.prosecco.it/en/scheda-itinerario/the-prosecco-wine-road/

This is way too much for two weeks, and I am a fast mover.

Ideas:

If you had to drop Cinque Terre or the Amalfi Coast, which one would you keep? If you don’t care about Venice, then fly into Malpensa (Milan). Take the train to Verona & stay there. It’s a straight line north to the Dolomites, so you can pick up the car in Verona when you’re ready to leave. Give the Cortina day to Ortesei. There’s plenty of great hiking in that area, and if you have a cloud-covered day, you still have some good days. Leave the car in Verona & train to Florence. Or pick a beautiful Tuscany spot and keep the car. If you’re finishing in Florence, just do a RT flight from Milan & probably save some money & time. I like the MOXY at Malpensa for my night before flying home from Malpensa.

Thanks everyone! Really appreciate the tips and fast replies. So many places to see, just more reasons to come back! Very good to know that the commutes are typically longer than anticipated.

I agree that your travel times are practically guaranteed to be significantly longer than what Google Maps says. Not least because September is still high season. You have set an absolutely frenetic pace, with not much time allowance tor finding "niche things" or enjoying honeymoony things. Or heaven forbid, Murphys law makes an appearance. With all the travel from place to place you are sacrificing a lot of sightseeing time, or any time to just soak up the local ambiance. If you could eliminate CT and allocate thoe days elsewhere, I think you would enjoy your time more.