Venice Vaporetto

Our B&B advised us to just "tap in" with a credit card. (We used Apple Pay on our phones) The system will automatically determine best pricing. One evening, there was a woman who had purchased the pass, and it would not scan at the gate. No one was in the ticket office, so she was unable to board. Those of us who were utilizing "tap in" were good to go. Just be sure that you do not use the lane that is reserved for the residents of Venice. It is clearly marked. Enjoy the trip!

You essentially need to take 5 rides to make the 72 hour pass cost effective. From the station to your place and back and your proposed trip to Murano and Burano covers that many trips. There is also something to be said for the freedom to take the vaporetto whenever you want as well as not having to find tickets. I don't think the Fondamente Nove station where you may get on for the islands has a ticket booth.

There is, of course, a large very busy ticket booth across from the train station where you can buy tickets and passes.
Validate your ticket as you get on at the reader every trip whether you're using a pass or not.

Enjoy Venice,
=Tod

If you're going to be in Venice and it is hot, the convenience of being able to hop on a vaporetto
at will instead of walking in the heat and crowds is worth having (even if the vaporettos are
packed also).

If it's not a huge expense in your travel budget, I'd buy them.

Riding the vaporettos will also reduce your wear and tear and give your kids a break once in a
while, which will increase your time spent sightseeing. Consider the overall expense of the trip
against the incremental cost of the pass vs the individual rides you already know you will take.

I've heard that Venice has implemented a tap system - maybe actually called "Tappy"? I haven't used it but I've used similar systems in other Italian and French cities. If you plan to use it do your homework - most systems demand a separate credit card for every rider which can be an issue for larger groups especially with kids. Using passes allows on person to manage all of the tickets - or at least the kids - without having to juggle multiple credit cards. Or maybe a hybrid system where each adult has their credit card and the kids have passes that they use or that an adult keeps hold of.

I'd say do whatever makes you most comfortable. I personally like the separate physical pass card and not having to depend on my phone to be awake and active while in a runstile with a line behind me. It makes me seem like a luddite sometimes but knowing I can get home at the end of the day without having to find a place to make sure my phone is charged makes me more comfortable.

Enjoy Venice, it's one of my favorite places,
=Tod

For transport to Marco Polo airport, is Alilaguna the only or best way?
How long has security been taking around 9-10 am?

This thread has the transportation options from the airport
They are basically the same to the airport

https://community.ricksteves.com/travel-forum/italy/getting-to-venice-from-airport