On the way from Milan to Venice, I'd like to stop in Verona for a few hours. From what I've read, with an IC train you can get on and off whenever/wherever you like since reservations are not required. Is this correct?
I have the same understanding. I've done this on an R train but not an IC train. However, as with the R trains, you are not guaranteed a seat. www.trenitalia.com is not really clear on this on their website. If you do a dummy booking on an IC train from Milan to Venice, I see "mandatory booking" on the cost page. However, when I do this on www.bahn.de, the German website, it shows no reservation required for and IC run. Finally, if you go to www.italiarail.com, you will see a chart showing which trains in Italy require a reservation. The IC train is not on the chart.
I would vote for no reservation required but let's see what others have experienced.