Just in case it needs to be said or on the off chance someone else is even reading: major spoilers herein.
Goth girlfriend = drug overdose (what happened to Jesse's MILF interest?)
Jane didn't OD. Walt let her choke to death on her own vomit in her sleep, neglecting an opportunity to save her life. He does so out of a paternal instinct towards Jesse, and out of self-preservation, with an arguable dash of pure cold-blooded revenge. It's a complex soup of motivations playing into a unique situation, all transmitted without any dialogue at all.
That's a lot more interesting than a simple overdose. I'm not sure there's a better representative scene of the show's namesake, really. If one had to choose a definitive moment wherein the audience is watching Walt "break bad," I'd vote for Jane's death.
New girlfriend with kid and kid brother = both kids get endangered/killed
I actually agree with you here. Andrea and Brock and his cousin (at least once he became known as her cousin) all felt like mere plot devices to me, one of the closest instances of BB settling for conventional TV show bullshit. Not my favorite characters, and some of the show's sketchiest, furthest-fetched scenarios revolve around them specifically.
Three buddies dealing = fodder for turf war (I was expecting two out of three)
Well, a turf war is going to expectedly be a part of a narrative about illegal drug-dealing, yes. Didn't see a problem with this. I love the way Badger's apprehension is utilized as a way to introduce Saul. I appreciated the mix of comedy and drama in the way the turf war plays out. Walt and Jesse's ineptitude demands that unfolding events be somewhat ridiculous, but the show still conveys the gravity and danger of what is happening on the whole.
If it wasn't going to be an old boss it would've been another character introduced for that purpose. I don't see why it being an old boss is a particular problem.
Bookkeeping errors in old boss' company = spills over into Walt's money issues
I have a few quibbles with the mechanics of this, and I do think you raise an interesting possibility of a direction they could've gone that would negate the necessity of making Ted a moron. That said I didn't really object to this as a way to stack Skylar's own closet with a couple of minor skeletons, thereby giving her something to lose (and something to protect) as the situation evolves. To me, it played out interestingly. I have bigger problems with the way Season 4 resolves the Ted thread (too much an easy out) than with the things that led up to that point.
I also loved Walt's reaction to the affair.
Constantly having to wonder who wants to kill whom and why gets old really quickly. Actually having a character say the words, "You can't/won't kill me," is only topped by that old invitation for explication, "But I don't understand," as the most hackneyed piece of dialogue ever.
Is there really that much ambiguity in this department? Walt's own motives tend to be a little erratic, but that's in keeping with his character and what his character is going through. Gus's seem pretty straightforward for the most part, as do the cartel's.
I only recall one instance of Walt saying "You can't kill me" -- or no, two I guess -- and they are both terrific scenes. Walt sells the sheer audacity of it. He doesn't know when to shut up, and it's part of what makes him fun.