MCing an AW game is a blast. If no one in your group wants to, may I ask is it because they feel daunted by the prospect or simply find the experience entirely distasteful? It would probably turn out better if you guys decided to create characters, create the world, and then pick an MC. Then alternate either every short few weeks of gameplay to give everyone a ride, or hell even alternating every session and passing the character sheets around in the same pattern. As a social exercise you'll quickly be able to see who enjoys what, and if you guys can pass a game around every session, I'm sure you can work out rules to then play all together at once. A game without an MC will almost certainly be worse then the same game with one.
I mean, countdowns and threat types never need to be referenced, neither does a particular scarcity need to be pin pointed. These are tools that enable the MC to stay true to the narrative, but they're not required in order to do so. Neither are hard moves, they're pretty clear, bad shit comes out and right when its about to slap you in the face, you get to react. I mean, assuming you set up a shared agreement on what types of things can happen, its certainly possible that everyone around the table speaks up and you guys go with what sound narratively the coolest. In my experience, about half of my players prefer to miss a roll because the game gets so much more exciting and tense (granted not every roll).
The biggest loss dropping the MC is continuity. What that NPC says one day, in the hands of one guy, for a reason they might not say out loud but isn't necessarily hiding... might get oversimplified or just plain altered when someone else speaks up in their stead. A person missing a week could potentially cost the game tons of information. PvP becomes messy, but really fighting all together is even worse. If you're passing around a stick rather then all speaking up, then one persons lack of spark can disappoint everyone else, judgements over actions or patterns of less then cool calls can easily threaten the joint venture. It is far better to have that arbitrator to make those calls. The key is finding someone that wants to be that guy.
That said... as an MC you can shoot things. I cannot even count the number of times I've had one NPC yank out a gun and just shoot someone else in the room. Even when that someone had a name history and all the interpersonal ties. You're allowed to blow people away, you should. You're looking at the NPCs through the cross hairs, not just for players to kill them, but also for you to rip them into pieces. You can even roll if you want, but that'll just clog shit up and slow things down at best.