I've been to Cilento twice and Croatia (Istrian Discovery) and I'm off on the Tuscany trip (which I am very much looking forward to) on 3rd October.
To be honest I cannot remember toilets on any of the coaches that we used. Going out to the hotel in Cilento the first time we had a comfort stop (3 hour transfer) and also coming back to the airport. The last time in May we (the Stansted crowd anyway) were transferred by mini bus (not plesant) with no stop.
Istria again was a 3 hour transfer from Zagreb but we had a comfort stop going and coming back. I understand the transfer to and from the airport for Tuscany is only short?
As for the trips? Certainly the day excursions that I have been on have not been an horrendously long time on the coach before you stop.