Venice/Scuolo Grande de San Rocco (Scuolo San Rocco)

The Scuola is not a church, so it won't be on the card.

I'm not sure what you're looking at that says there are 16 churches. The official website says it's 15 and lists 15:
Chorus Venezia

It looks like the Venice Card has become the Venezia Unica, covering both the Chorus Churches and the city-run museums, but Scuola San Rocco is not on either list. Plan on paying the 10 euro entrance fee in person. See also some recent updates about vaporetto/transport passes at http://www.ricksteves.com/europe/italy/guidebook-updates.

Thank you both for your replies! Much research yielded no responses, but it seems the most clarity comes with Michael's answer indicating that the scuolo is not a church. I had actually wondered about that and tried to find the translation of that word. It looks, in photos, like a cathedral. Do you know what a scuolo IS?! Thanks again, to you both!

Ah! Now that I have been put on track by Michael, I discovered that this is a school. Problem solved!

Let's get even more confusing. There is a church next to the Scuola.

I saw that! There's apparently a church that is part of the school and also the Basilica dei Frari is there, as well. I'm gradually getting it all straight! Now I want to find out how to get online tickets ahead of time for all this stuff - the Venice Pass covers way more than I want to/need to see, or have time to see, and I do want to see the Doge's Palace/Museum Correr and the tower, both of which require separate tickets. Lots of research to do! Planning! It's fun, and I'd rather have done what I can before the trip, have voucher in hand and not stand in lines! :-) It also gets me acquainted with what I will be seeing and spread out my spending!

A Scuola can mean two things in Italy. It can be a school or an association of trades people or it can be,as is the case with most of the Sculoa's in Venice, that they are a church affiliated school or benefactor group. Most of the Scuola's in Venice look like a church from the outside but inside they look more like a meeting hall though they can be very ornate do and decorated with paintings and sculptures.

You couldn't find a definition for "scuolo" in Italian because the correct word is "scuola" which, as you now know, means school.

And you don't need online tickets for San Rocco, either the Scuola or the Chiesa (church). There won't be a line. FWIW, the magnificent art is in the Scuola, but the Chiesa has some nice pieces as well.

And there won't be any lines for the Frari either.

Ticket advice for Venice. Scuola and Chiesa San Rocco - just buy your ticket on site. It's easy to get into to see the Tintoretto's and other works. No charge for San Rocco Church. Just stop in for a pleasant visit. Frari Church - again buy your ticket at the door. No line. Download a free RS audio.
on Frari Church. You can also watch a RS episode in advance. There are even some free music concerts at night in Frari. Correr Museum and Doge's Palace. Go to Correr first - no line. Buy a combo. ticket and enjoy Correr. You may even want to eat at the Correr Cafe - a good choice for St. Mark's square. Be sure to use toilet facilities before leaving! Then, march or stroll across the square. Skip the long line for tickets for Doge Palace. Go to reserved ticket line with your combo. ticket and cruise right in. Enjoy!