Here is my input on your Bamfield questions:
I think that the place where you are thinking of with moorage and accomodation in a travel trailer is Seabeam Lodge. Great place to stay and the owners are very nice.
As far as the best time to go, you'll have to ask around, but I make a trip there in mid July and do quite well. I don't think that it is the "best" time to fish there, but it works for me.
As far as whether to run out by boat or to tow out by trailer, my vote definitely goes to running in by boat. If you want to, you can drive part way to China Creek, and then launch there. I have just seen too many people have problems with their boat and/or trailer when they tow in.
I hope this helps and I'm sure others will be able to provide more info.
Fish Wish