Everyone else has covered 1-4, but I wanted to say something about the 1st Session worksheet and Fronts.
I had trouble with the 1st Session worksheet too, because it doesn't really fit how I was thinking about things and doesn't really give me the tools I felt like I needed when running the first session, aside from the list of names. Mostly, I filled it out after the 1st Session was over, to help me think about Fronts. Things were just too fast and exciting for me to stop and write everything down and think about where it fit amidst the fundamental scarcities, etc. Next time I start a campaign, I'm going to make a new 1st Session sheet that gives me more useful tools and info at my fingertips. So use it when it's helpful, but don't feel like you're breaking the game if you don't really use it all that much. Just follow the players around, make your MC moves when necessary, and barf forth apocalyptica. Those are the key things to do, first session.
I was also talking to a friend recently and it turns out we both make Fronts backwards from what Vincent suggests in the game. Whereas Vincent says to make your Fronts first and then use them to generate a bunch of subsidiary threats, we both find it makes more sense to make a whole bunch of threats, based on the NPCs and what seems to be out there in the game, and then group them into Fronts based on theme or origin or geographic location or what have you. So it can really work both ways and, honestly, I find the latter way more natural but maybe you'll like Vincent's way better.
In my current game, the Fronts are very geographical right now. The threats on the PCs home space station are all a Front, even though the threats are pretty different. The stretch of scavenger space where they go for supplies is a Front containing a number of threats. There's Fronts back on earth and on the moon if they ever go there. However, as the game progresses, I expect that this is all going to mix up pretty fast. Some of the junklords might come live on or take over the station. The PCs will bring threats from the station with them when they head to earth or the moon. The PCs will form gangs that are made up of threats from locations outside the station. The PCs may eventually leave the station to go live somewhere else, full of its own threats.
So, my recommendation is, at the beginning, just group threats into Fronts the way that is the easiest for you to keep track of. That may not necessarily be geographical. If you're game is set in a zombie plague, maybe all the zombies are part of the same Front and so is the infection that causes people to turn into zombies. But just go with what makes sense, because it's mostly just a shorthand and organizational thing to make the MC's life easier. And the players are sure to mix it up and move things around later in the game anyway, so you don't need to worry about making it too complex in the beginning.
Hope that helps.