Travelling in Venice

1. About 1 minute. You just walk through it. It will take longer to wait for your luggage at the carousel. Since there are no direct flights from your location to VCE, I assume you'll be going through another European hub first. That is where you will be doing the passport control (immigration), not in Venice. 2. Not hard, just ask and they'll direct you to them. There are several every hour. 3. Yes.
4. You must change reservations at the ticket window first. Each ticket is train specific and seats require reservations. There is no reason to buy ahead however, you can buy at the station. Flights are subject to delays so it's hard to predict which train you'll be able to catch. I have no idea where Genoa Piazza railway is. Where do you need to go from Venice?

Elayne, you are seriously over-worrying. Arrival at Venice is so easy. You retrieve your luggage and walk out of the front door. Thee are two airport bus systems (ACTV and ATVO) that have airport buses to the Piazzale Roma. Being airport shuttle buses, they take luggage. Fare is about 7Euro for the ride. You catch the vaporetto water buses at the Piazzale Roma. If you need to immediately take the train, you can walk to the train station from the Piazzale Roma. It's about a 1/4 mile. There is no such railway as Genoa Piazza Railway. There is a Genoa Piazza Principe train station in Genoa but this train station is on the opposite side of Italy and about 5-6 hours away by train. Please explain further.