Oh boy, something else to disagree with you about! Yay.
Seriously though, I do have a difference of opinion with you on the person of Prince Charles. While I'm not thrilled with the House of Windsor in general, I am content to say I am a subject of his mother as well (being a Canadian citizen.)
I've always thought of Charles as being a bit 'dim.' This is the man who talked to animals and sat in the triangle if I remember correctly.
Call me nutty, but I talk to my dog. If anything (having come to know something of the man, apart from tabloid splatters and tacky stereotypes of the royals being nothing more than inbred wasps), he strikes me as someone who was always a bit whistful, and perhaps even something of a prankster. He certainly seems to have a sense of humour.
Besides, he was a monster to his wife. His indifference towards her drove her to her early death. He may have been forced to marry her even though he didn't love her and Diana may have been naive to believe that he loved her but that's no excuse for the way he treated her.
Couldn't be you're confusing his marital difficulties with how intelligent or otherwise kind/interesting a person he may be.
As for the marriage, from what I know there was enough blame to go around. Unfortunately, because Charles was/is not a beautiful, mesmerizing young woman with a soft voice and an almost angelic air to him, he will never get the sympathy or even handedness that any assessment of him deserves. While it is shameful that he committed adultery, his wife was also an adulteress, and by no means an angel. Even her charity work (as good as it was) was over-rated (for example, considering it was only a fraction of the efforts the less comely, and less media savvy Princess Maragret did over the years).
In the end, I think Diana was extremely niave, and was in the end, not willing to "tow the line", and make the personal sacrifices that come with being nobility/royalty.
With that said, she also had a good side (like most sane, normal people do), and did do a lot of wonderful charity work. However, balance is necessary (the whole "St.Diana" mythos being quite frankly, absurd.)