Is it worth purchasing a Rome Pass if you will be on a Rick Steves tour? We will be arriving 2 days before tour starts and would like to visit a few places not on tour itinerary and also use public transit.
It depends on what you want to see that you won't be seeing on the tour. Check the attractions listed on the Roma Pass and their cost -- factor in the advantage of skipping the lines. If you want to see the Borghese gallery, for instance, you would still need to make an appointment even if you have a Roma Pass. You can also buy an all-day transportation ticket as needed. And some places (lovely churches, parks) are free to all.