I've mostly played the game in forums, so I don't have a lot of experience when it comes to playing the game in real-time.
Like you, I've generally found the fronts a pain. But that isn't to say that there aren't some good stuff to say about them.
First off, they have the threats which are a good inspirational tool, in that they get you (or at least me) to look at things from a different angle. Making a landscape or afflictions an active opponent is something I probably wouldn't consider without the list of threats. And keeping to the list of threats forces me to consider only threats that are active in some way (even adding moves you can make on their part).
And having to create 3 or 4 threats for each front forces you to populate the setting. You can't just have the rival hard-holder and his gang, you need at least two more.
Having an agenda/dark future forces the world steadily towards the precipice, giving the players stuff that they need do something about.
It's all stuff that you don't need the fronts to handle. You could do it without fronts. But then, neither do you really need the MC's agenda, principles or moves. But they are very handy too. I generally find that even when I don't play according to the rules, the rules can still teach me a thing or two.
You said that you did your world-building stuff. I too like world-building. And that might be where fronts fail us. Try this out for an exercise. Make two fronts. Do it using the checklist; select scarcity, make threats related to the scarcity, make dark future, etc. Don't at any point try to force your own characters and places into the front, instead let the characters and places spring from the front.
Feel free to throw the fronts away afterwards. The point of the exercise is not to use the fronts, but that you might learn a thing or two about creating threats (in the the form of warlords, grotesques and the overall front agendas) for the players to interact with, instead of a nice and tidy world for the players to interact with. One provides them challenges and opportunities to grow, the other risks being a mere theme park where the players get to kill people.
Not that I'm saying that you are normally MCing themepark worlds. What I'm saying is that you are unlikely to find a world with more threats (and therefore challenges), than one guided solely by fronts.
GM's Agenda: "Make Apocalypse World seem real".
Would someone shoot themselves in the head for drugs? No.
Apocalypse World tries to make it very easy to avoid ridiculous outcomes by giving a good set of guidelines: the Moves exist under the direction of the Principles, the Principles aim towards the Agenda. So yes, there are limits to Manipulation, and it's about what makes sense in light of the other rules given to you.
Best Answer
At the start of the first session, everyone pays 1-barter and goes on to live the 1-barter lifestyle.
And that's part of the purpose of the first session, isn't it? To walk through just what that 1-barter provides for you, and maybe who gets that barter and in what fractions? "Let's follow the characters around for a day and get to know them. Cool?"
Why do it explicitly, instead of just saying it's handled for the first session only and giving people less starting barter?
Exceptions are weird and it's better to fail safe than fail deadly. So in the opposite case, where everybody starts down 1-barter and it's assumed the first session is taken care of, everybody still has that Barter section on their playbooks saying "at the beginning of the session". What if somebody brings that up and the MC can't find the right counter in the rules? How many playbooks only start out with 2-barter, would start out with 1-barter in the revised case, and head into next session flat broke? (The Angel, the Chopper, the Gunlugger, and the Skinner, for reference. 4 out of 11.)
Everybody losing something means everybody feels a little pressure. Those 4 out of 11 feel it the most, of course, which is why that setup section goes on to say:
But everybody just spent some barter and knows that every time they sit down to play they'll be shelling out more just to keep going. So everybody, except maybe the establishments of the Hardholder and Maestro'd, is going to be looking out in that first session for who's going to pay them and why.