Frannie,
My experience is similar to what Angela described. I haven't taken the Italy 17-day tour, but have taken three other RS tours (and have another one booked for this year).
To answer your questions....
1) RS Tours have been using more "upscale" Hotels over the past few years, so the possibility of a "shared bathroom" is quite remote (but it could happen in rare circumstances).
2) The Bus times have been fairly accurate in my experience. There are scheduled stops at fairly frequent intervals, both to allow the passengers to get some refreshments or use the WC, but probably more importantly to allow the Drivers to have their mandatory break. European regulations with Drivers are VERY STRICT, and the Buses have automated Meters installed. Drivers who operate longer than the allowed period can expect STRICT fines!
3) So far I've found the RS tours have been somewhat "relaxed" with their starting times. Most times breakfast is from 7:00 - 8:30 or so and the Bus departs at about 9:00. HOWEVER, that depends on the tour and the Itinerary at that time, so it's a good idea to allow for some variation in that.
As someone else suggested, contact the RS tour department as they'll be able to provide the best information.
The Italy 17-day tour is one of the most popular. Have fun!!!