Staying at Luca's place was one of the highlights of the trip. I was a little worried about staying away from downtown Venice, but it was a good choice for my group and I. Luca gave us information about how to get everywhere and was always available to help whenever we needed it.
The bus stop is a 5 minute walk away from the apartment, and the bus ride into downtown is around 10-15 minutes. Purchasing the bus ticket that Luca recommends will save a ton of money for you and your group. There are a couple of amazing restaurants and cafes within a 5 minute walk from the apartment making everything easily accessible without a car.
I had a group of 3 total and we all fit very comfortably in the apartment with two of us sharing the main bedroom, and one of us on the futon that could go down into a bed.
I would come back and stay here if I ever come back to Venice in the future.