In no particular order and not all of these could happen:
-Jesse dying, his life was so bad anyway
-Jesse escaping himself by killing the Nazi's in someway
-Any meth explosion, like come on, how do they make a million pounds of meth with no explosions? Especially once it was rigged up underground or in that barn
-Jesse and Brock reuniting
-The ABQ Police Department actually being worth a damn. You think a meth kingpin could just waltz around town like it was nothing if this happened in real life?
-The Stevia Ricin switch not being so blatantly obvious
-How about a flash forward of what happens with Jesse. Is he a chemistry teacher? Is he a woodworking teacher? Is he back on drugs? I mean anything.
-If they were gonna bring up Grey Matter, why not show why Walt and Gretchen broke up
-Walt doing one last cook
-Walt trying meth just to see what it's like
-Walt blowing up the lab and him going down with his ship
-A true flashback to this quote: "Chemistry is... well, technically, chemistry is the study of matter, but I prefer to see it as the study of change. [...] It is growth...then decay...then transformation. It is fascinating, really."
-Todd seeing Lydia die so he knows how that emotion feels
-Jesse actually killing Walt.
I have more. It did what it needed to do but it left me wanting something a bit more.
Most of what you say here would have made this episode worse in my opinion.
Walt trying Meth, blowing up the lab, etc. Seriously? This show is so much more than explosions and violence. It's an intelligent show and that would have dumbed it down.
The ABQ police dept not catching Walt was explained by multiple fake reports coming in.
Jesse killing Walt is not how this should end. There was a mutual hatred/love/respect that was consistent throughout the show. Neither one of them could ever kill the other. If they could have it would have happened long ago as there were plenty of opportunities. They saved each other more times than I can count.
Jesse meeting up with Brock? What, do you think Brock is still at the house where his mom was shot? You think they are going to let a known convicted drug kingpin just take over custody of him? There is no clean, quick way to wrap that up so they left it up to the viewer to imagine what might happen and hope for the best for both of them. That's not a bad ending.
As far as Gretchen and Walt, who cares why they broke up? The way he got closure with Elliot and Gretchen was unexpected and perfect. Figuring out it was laser pointers was what ruined it for you? Really? I think half the audience figured that out but it wasn't the point. The threat was still intense. Were you just wanting them to get gunned down? You seem to have wanted this show to go out guns blazing but that isn't what this show was.
What made Breaking Bad great to me is the intelligence behind all of it. How hard would it be to have all of these things play out as they did without it seeming extremely unlikely that it could actually happen that way. Nitpicking the ABQ police for not being smart enough to catch Walt is pretty minor. Look at all of the dramatic things that happened the way they did and very very few times were we left thinking, well that's a stretch because it would never happen that way. That is brilliant writing.
The violence that happened wasn't for the sake of having violence, it was to draw out emotion in the characters. It's why we in some ways felt bad for all of these very bad characters. Gus having his partner shot in front of him, Jessy and Walt were terrible people but we empathized with them.
I'm really not sure why people wanted a gun fight and explosion laden finale. That would have been completely disappointing as it wasn't what the show was about, ever. This was perfect.