Hi John
The tourist information centres are very helpful, and it's well worth calling in to get bus timetables, accommodation lists etc. If they are closed, there is sometimes a list of B and Bs with vacancies in the window. If open, they can help in booking, sometimes for a small fee. If a B and B was full, then they could sometimes recommend somebody else to try. I also used the accommodation list at the back of the SWCP handbook. I think they note in the guidebook if there is a stretch with few B and Bs, and that's probably where you need to book ahead or be prepared for a longer day. I think the only time you might find it difficult is the bank holiday weekend at the start, but there's plenty of places in Minehead so it shouldn't be a problem.
If I did it again, I don't think I would take a tent. What really makes the difference to knees, blisters etc is not carrying too much weight, as I'm sure you know. You're planning to keep up a good pace, too. Also, despite some lovely times camping, I'm a wimp and don't much like camping in bad weather, so I keep the tent for trips in warmer climes like Greece. The only reason for camping would be that it's obviously a lot cheaper, especially if you are looking for a single room - sometimes hard to find and you can only get a tiny discount on a double. But as somebody else said, you can always post the tent home if you find you don't need it.
Impossible to say what were the best bits - overall it's the variety and contrasts that make this such a wonderful walk, and it also depends on the time of year etc - eg if the foxgloves are out along the cliffs (more on the south coast).The area around Tintagel and beyond is lovely, including the hostel. I saw seals around St Agnes, then just beyond St Ives.
Jane