Only 10 days and counting.... I remember seeing a post recently about Metro frequency, but can't find it now, and not remembering the answer. We have a reservation for the 9:30 Scavi tour at the Vatican. Our hotel is a block from Republicca Piazza. What time should we leave the hotel in order to pick tickets up by 9:15, without cutting it too close? An Hour? Thanks!
60 min is more than enough. The subway is frequent during the day.
Trains for the Linea A, at that time of the day, run every 3 minutes in each direction (every 4 minutes in July/August and Sundays).
The train ride from Piazza della Repubblica to the Ottaviano station is about 10-15 min. max. Then you have to walk from the Ottaviano station to the Vatican Museum, about 10 min at a leisurly pace. So one hour will be more than enough. You have time for a cappuccino and a "sfogliatella" pastry on the way there.
Yes, along Via Ottaviano from the metro stop to the Vatican are many inexpensive places to eat and drink. I stayed near this area for a week last June.