Well, for someone who disliked the show so much, you sure ripped through those four seasons mighty quick. Not that that in itself discredits your opinion; I had a similar experience with Lost. I snorted down Lost like the TV cocaine it was, but my overall opinion of it wasn't particularly glowing.
I think "every plot point telegraphed" is the kind of criticism that's easy to toss out there about any show or movie you dislike. It sounds good, but I can't think of any television show I've seen you couldn't say the same thing about. I think BB can actually be pretty subtle in its conveyance of plot points, but it does tend towards a ponderous, syrupy quality in the manner of their transmission. Telegraphing plot points is part of what a narrative is supposed to do; I think it's more a matter of how well you're enjoying the pace and manner in which it happens.
I just plain disagree about the dark comedy comment -- I think Breaking Bad is rich with dark comedy, some explicit and some subtle, and the show's consistent funniness is a big part of what I appreciate about it.
I've no idea what the shifting allegiances comment means, and I've never seen any Pirates of the Caribbean movies, but it's difficult for me to imagine Pirates of the Caribbean 3 representing the formal "death" of any narrative convention. I mean, it's a sequel to a children's movie based on a theme park ride.
As to filler, the up and down, two-steps-forward-three-steps-back ebb and flow does get a little redundant in and of itself, but they find new things to explore about the characters and their respective situations each time it happens, and never allow themselves to get sloppy with the execution of their ideas. As an audience member I never feel taken for granted, which is a sensation I find rare when it comes to TV shows. I can understand its slow pace not appealing to everyone, but I really don't think BB is any worse in the "filler" dept. than any other critically acclaimed show I've seen. That's a pretty common symptom of TV shows given their serial nature. At least BB isn't repeating the same formula each episode. The narrative evolves and is following a clear trajectory. I think a close examination of most individual episodes of BB would reveal them to be pretty narratively tight. Each scene usually has a purpose which is important weighed against the season it's housed in as a whole. Some of the Marie and Junior stuff I would agree is extraneous, but mostly because they don't seem to have much of anywhere to go with those threads, and because they are fundamentally less interesting characters than the main cast.
"Soap opera," sorta, but I don't think there's anything wrong with that in and of itself. You could fairly call most dramatic serialized TV shows juggling a lot of characters with romantic relationships between them soap operas if you cared to, but there's a big difference between Breaking Bad and All My Children.
I do agree they could compress BB to 30 minute episodes if they really wanted to, but I really enjoy the way Breaking Bad explores its own space a little. It's so rare in a TV show. I could understand someone finding its tendency towards lingering shots, ambient tonal segues, and general unhurriedness a little tedious, but I think it compliments the setting and mood of the show very nicely, while allowing room for suspense to accumulate and creep up on you over the course of a full season. Gilligan as a student of Leone makes a lot of sense to me, the show has a very spaghetti-western flavor at times, just displaced into a very unusual context.
PS - Although it seems to be an unpopular episode, I liked "Fly" a lot. The metaphors couldn't be more obvious but I thought the episode functioned nicely and broke up the season in about the right place. It is so self-contained and self-referential it almost could or could not have even happened, in regards to the larger narrative. I.e. it could almost exist in the same "meta" bubble housing the Heisenberg Spanish music video, etc. None of that makes it good or bad, but I thought people were hard on it.