The bike may be somewhat at fault - can't say as I don't know about Jamison. The wheel is definately at fault and that most likely is the wheel makers fault. You might only expect 3 to 4K miles on a chain, and brake pads wear (although I have not had to replace my campy pads in over 10 years). What I would say is that your bike dealer sounds like a jerk if he was putting the blame back on you for riding the bike which is what it was ment to do. 6.2K miles in 2 years is a lot of miles and everything you listed except the bad wheel I would say is reasonable maintenance.
As far as a road bike - there are so many good choices and it seems you are riding enough where you should know what you like and what will work for you. I have had great luck with a lugged steel frame that I had built up with a good group - it is a very comfortable ride yet fast and responsive. I also bought a CF Specialized Tarmac which is fast and fun but not quite as comfortable on long rides.