Thanks, Noofy. That helps a lot.
I also realized that I actually own Apocalypse World. I'd even started reading it, and was greatly enjoying it, but got distracted near the end of the character packages and never got back to it. So I'm reading through that as well. Things are becoming a lot more clear.
So, let me see if I get this right...
If there's a lull in the action (everyone's looking to me to push things forward), then I should do a soft move.
If the player rolls a 7-9, then (typically) the action's rules should dictate what I do.
If the player rolls a 6-, then I can do pretty much whatever I want as long as it flows naturally from the story and doesn't violate the principles.
Do GMs typically make moves after a character succeeds with a 10+ roll? Or do you move on to the next player at that point? Or does it depend on the situation? It seems to me that I'd often want to show the NPCs reaction to whatever the player just did. I guess that may or may not be a move, depending on the situation.
Basically, I think the "Being a fan of the characters" principle--when interpreted rather broadly--really helps on setting the limits. I'm still a bit uncomfortable with some of the examples--particularly when it comes to things like "dragging someone away", which I've seen mentioned a few times. I guess if it's a PC, I'd only use this as a soft move. The person is in the process of being dragged off--setting up a situation that everyone needs to respond to. Rather than making it a hard move, and having the character simply removed from play without any chance of responding. Of course, if it's an NPC being dragged off--well, then things are different. I don't have to be a fan of the NPCs.
I'm also still a little confused about how many of the actions in the Bloodstone Idol adventure are supposed to work. Especially since most of them don't have any rules or descriptions--just the move name. Without understanding the intent behind the move, the name often isn't enough. Of course, this wouldn't be a problem if I was creating my own adventure and my own moves.
The principles are interesting. Often, when you look at more narrative games, you can tell a lot about the designers bad experiences by how they shape the rules. For example, the principles put a lot of explicit emphasis on things like not railroading the characters. There's a softer, implicit emphasis on not violating the character's integrity, providing the character with interesting choices, and making sure the choices have an impact on the game.
If I'd written them, I'd have put a much more explicit emphasis on the latter, and a much softer emphasis on the railroading/gm story issue. Which, in turn, says a lot about the problems I've had with games in the past.
I also like the description of soft vs hard that you provided. That really makes things clearer. Unfortunately, none of this information is really in the basic rules. Which is a shame. At least for me, it makes it hard to even think about running the game--at least until I did some additional research and became more comfortable with the ideas. I think I'd probably feel comfortable running it now--though how I ran the game and how you ran the game would probably be very different. That's not necessarily a bad thing.
For example, I think I'd often favor -1 forward modifiers (which only affects the next move, yes?) over actual damage to simulate many minor damaging effects--and leave actual damage for when the bad guys really carve a piece out of someone. At least from a theoretical standpoint, I like the way it has a mechanical affect on the action, but it's temporary. It simulates being rattled or stunned by the attack, but the character can still shake it off. Of course, I'd have to see how it actually feels in play....
And, I look forward to seeing the complete rules.