Ummm..... you are aware that wrestling is scripted, right? Assuming you aren't, here's a few pointers.
1/ Bret himself admits that he was lacking in the charisma stakes, having less mic ability and so on than many others like Shawn, Hulk etc. He was however, in good physical condition for a guy who was only six foot one, and contrary to your opinion (which you are of course entitled to) is universally acclaimed as one of the greatest workers and story tellers in wrestling history. Vince himself puts Bret second only to Buddy Rogers in that regard.
2/ Bret is, I admit, not one for what he probably thinks of as false modesty. He genuinely believes that he was a consumate professional in that he didn't miss more than one town in nearly a decade and a half and only caused about two accidental injuries to colleagues in his entire career.
3/ After Wrestlemania he was actually "gone" for about six months, not a year. And in that time he still worked foreign tours for the WWF, he just wasn't doing regular TV work.
Until Wrestlemania 12 he had been working constantly since before Wrestlemania 1, so he had been working three hundred days a year for more than twelve years. Considering most wrestlers go between four and six years before taking that sort of amount of time off, I hardly think Bret can be blamed for doing so and it sounds rather silly when someone tries to.
4/ Bret's cockiness and sniping at Shawn: On his return he was supposed to work a program with Shawn (after Shawn finished his run with Sid). It would have involved Shawn first putting him over (at Wrestlemania 13) and then Bret putting him back over around the time of Survivor series (there's irony for you). After an absence of six months from the TV shows, if Bret hadn't been trying to get heat on Shawn during his time off, there would have been zero intrest at the start of the run, which would have been a financial blowout for the company. Why the hell wouldn't he have been critiscising Shawn? Again I ask, you do realise this is all scripted right?
5/ Bitching and moaning/anti-US: You do realise this is all scripted, right? I'm beginning to seriously wonder.
Bret actually found the whole angle rather absurd, though fun at times when he was in Canada. He found it so because he's actually half American and half Canadian. His mother is from New York and he carries a United States passport.
The angle where he turned against America was due entiirely to the fact that the crowds were beginningt o cheer people like Austin and boo characters like his. The fans themselves became inadvertantly involved in the scripts of the WWF.
6/ Shawn was an amazing worker yes. I don't personally believe he was as good as Bret, because he was a snidey little two-faced bastard on a number of levels. He was certainly more FLASH BANG than Bret, but that doesn't make him "better". Just a different type of worker.
7/ Bret himself says Owen was the most gifted Hart family wrestler.
8/ D-X not taking themselves seriously. I'm assuming you mean on-screen. Behind the scenes Shawn, Levesque, NAsh, Waltman and Hall tried to turn the WWF into what WCW eventually became: a clique of selfish wankers who pushed themselves and each other at the expense of everyone else and stifled new talent. And we all remember how great WCW turned out, don't we? They were worth a paltry five hundred thousand dollars when Vince bought them out, compared to the WWF which was worth more than a billion. That is not not taking themselves seriously. The best thing that ever happened to the company was when Waltman, Hall and Nash fucked off to Turnerland and took their repellant philosophy with them.