Salzburg to Verona

That is the fastest way. Lots of people here use loco2. I'm a trainline guy myself.

That is indeed the simplest and most direct route.

so, if we go Salzburg to Innsbruck then onto Verona, do we go through the Brenner pass?

The Brenner Pass is the only rail route south from the Tirol, by train you have to go over the Brenner Pass.

I know we can go through Rosenheim or Innsbruck and would love to go through the Brenner pass.

If you don't want to do a time consuming detour (i.e. via Zell am See), the train goes both through Rosenheim and Innsbruck and then to the Brenner. However, the Austrian trains don't stop at Rosenheim, the first stop after passing through Bavaria is Kufstein in Tyrol.

There are single change itineraries connecting at Rosenheim at 6:56, 9:00, 11:00, 13:00, 15:00.

thank you all for the feedback!

the Austrian trains don't stop at Rosenheim

That is not correct, some RailJets do, some don't.
From Salzburg to Verona you have one train change. Depending on the connection, it can be in Rosenheim or Innsbruck.

A RJ going from Salzburg to Innsbruck never stops in Rosenheim since it bypasses the station on the so-called ÖBB bend. You can, of course, if you have time and money to waste, put together a connection in Rosenheim by combining an EC from Salzburg to Munich with another EC from Munich to Innsbruck. None of the only two RJ stopping in Rosenheim (at 21:01 and 21:54) could be involved in such a connection.

The OeBB website displays as the fastest connection between Salzburg and Verona is by going via Rosenheim. The RailJets stopping in Rosenheim are not headed for Innsbruck, but for Munich (e.g. RJ 60, 62, 260, 262).

An alternative without any train change from Salzburg to Verona is using the NightJet overnight train.

and would love to go through the Brenner pass

Won't see much from the Nightjet.

The OeBB website displays as the fastest connection between Salzburg and Verona is by going via Rosenheim. The RailJets stopping in Rosenheim are not headed for Innsbruck, but for Munich (e.g. RJ 60, 62, 260, 262).

Admittedly, I was a bit confused after reading your and Sam's post and was suspecting that the DB site gives wrong information. But now I understand that we were just looking for connections for different periods. All trains you mention are seasonal trains running between May 16 and August 5. Outside of this period they leave Salzburg at minute 56 at 8-10-12-14 and the transfer to the EC to Verona is in Innsbruck (from mid august to mid september traffic will be irregular due to several construction works). Transfer in Rosenheim - welcome to the innermost point of nowhere ... ;)

That is a problem we are facing in this travel blog very often: seeking travel information without giving an exact date or a date at all. People are not aware that there are a lot of seasonal changes in the timetables.