Suggest you look at www.viamare.com as this gives you full access to the Italy/Greece schedules. I haven't checked but if the ferries are no longer calling at Corfu, it's a fairly simple exercise to go to Igoumenitsa and catch a local ferry back to Corfu - not sure of the cost, but I think it was about £25 last year each way for a car and 4 passengers.
We have only done the Brindisi/Crossing once, about 10 years ago. Then we used Agoudimos lines. Very basic!
The best bit of the journey fromItaly to Corfu (particularly early morning) is watching Corfu and albania rise out of the sea the closer you get.