I'm not entirely sure if I know how to answer your questions but I'll try.
I'm also kinda liking the sound of a "scene based" system, but I have no idea the specifics of it. maybe that'd work better. Sounds a lot better than round by round combat, because I don't wanna take a month on things or several. For this reason I'd probably keep the player pool very small. Perhaps 2 or maybe even 3 at most to start. Maybe even just one in the very beginning. I have no idea.
I think the gist of your post is that everything should center around player experience and GM expectations? I'm pretty much ok with that, long as it doesn't go nuts. As for exactly what type of game I want, that's partially why this exists, to figure that one out. The general idea of what I was thinking is that you make some virtual space that's all your own, or as close to it as it can be. I'm looking for a sense of player ownership and hopefully the players would like the idea of having some little space that's "theirs." I do not want 1x1 bedrooms or anything (though at first basic sleeping stuff might be required, etc). The "mood" I guess of the game would be fun but serious (not fun/comedy/stupid etc).
I'd like each player to end up having their own customizable space akin to a home, perhaps a workshop, meaningful public spaces and people they can interact with, and things to do that are meaningful while interacting with the larger world. They may in time gain possessions, positions and power. They may not even strictly have to stay in the fort all the time. (I mean you know, don't go on globe trotting mission every day or something but yeah.... There isn't necessarily an invisible wall).
The idea being they'd create this and design it to look and feel cool. Hopefully it wouldn't just be "hallways and rooms!!!." In other words, not the usual dwarf fort that just gets stuck in the ground and left to do whatever.... I imagine dwarves making hallways, sure, but also plazas, vaulted halls, etc. That way it'll look cool and hopefully people will come back. They could also create their own industry/business/guild that does damn near anything. It could be a group of hunters dealing in meat and fur or.... I dunno.... a rock carving thing. Pick your poison really. The only limit is make sure it's something you'd actually wanna do repeatedly. I'm somewhat worried somebody would be like "I'm a rock carver," which would be fine, except their posts are gonna consist of "I carve rock things," which is ok, but imagine 40 or those posts. Would that be fun for them? I'm afraid it'd get old and I'd lose a player/they'd be pissed.
Also maybe you don't have to start your own guild/industry etc. Maybe there's already one or more existing guilds for that. They could actually help you.... Or, if you decided to start your own competing guild, maybe they wouldn't like you so much. If whatever the heck character you end up making is.... an armorer.... Then I can't imagine there aren't dwarven groups devoted to armor making. Maybe you pay them dues and they give you discounts? Maybe they issue challenges to you. Maybe they funnel you business to fill large orders even when the place you're in doesn't need craptons of a specific type of armor made? Who knows. Maybe they send you an instructor who teaches you how to make these awesome gauntlets or something. Maybe you get promoted in the guild and they send you an apprentice or four. Maybe you take over the whole guild or a part of it. I dunno. That seems to go into something the player would care about/ directly effect their gameplay. Might need some forethought though.
The other thing I sorta touched on earlier is what are the players gonna do that's fun and that's limited by what type of character they have and what skils. If you only do armor smithing, then I'm just worried that we're looking at "I make a peice of armor" x 100.... I'm worried that might not be fun for people/repetitive. I wanna give 'em something more, and I'm not entirely sure how to do that. One way might be to have players have a suite of skills related to one another. Maybe there's something akin to a flexible "class" (I have no idea what to call it, but that's close enough?) that has related skills. They don't just teach you about armor, but they also have you make weapons as well and smelt, and generally blacksmith? Who knows. Maybe you know how to make a wide variety of things that fort really needs out of metal. Maybe there's an "outdoorsy" class that deals with hunting/herbalism/skinning/some butchering and slight cooking? Maybe even some wood working in there, perhaps limited to say..... making arrows/bolts? See how that's one idea where your skillset is based around things that give you options to do in your environment.
Maybe you have several environments....
Also I'd hope there would be leisure activities for your character too.
You can also build a home or have somebody build it for you if you'd like to specialize in fighting, or a craft or who knows.
Maybe you have a couple skills in fighting and a craft?
The overall hope, however we get there is that players feel they have some reason to give a damn about the make believe world and that might even extend beyond the fort. You could visit and have reasons to care about things in other locations. You could have multiple homes/locations. Own a bar for all I care. End up being a dwarven tycoon or a general. End up being a pauper. It all depends upon what you do.
Keep in mind, there are going to have to be some NPCs involved but yeah.
@ Maximum Zero.
That sounds pretty reasonable overall.
Again, I get that you might not wanna get bogged down in the details, but also do you really wanna just type "I make a steel sword" 23 times? Not that you necessarily would or that it would all be the same, but am I kinda being clear enough?
I just don't want to have you have your whole experience in the game for a week be "I make a steel suit of armor." And then, "I make a steel spear." Then, "I make a Steel shield." After that. "I make a metal bit for the horses, preferably out of copper" Finally, "I get drunk at the ale hall (x4). I mean If that's how you'd wanna play, then I certainly wouldn't necessarily stop you, but I would like to give you more options.
I mean I'm simply afraid of it becoming repetitive and a chore instead of the fun it could be to have your own blacksmith's shop or something (whatever you end up doing).
On a related subject how long of a time do posts cover? I'm not going for the 6 second round in D&D (because that's too short) but yeah. I mean especially if I have 2 or more players, I want to figure out how to deal with the situation where the first player lists like 5 actions and the second one lists one short and simple one. What do you do with that?
I'm ok with making a lot of it up on the fly and perhaps it'd be better that way to a point, as long as it was consistent. I do want players to think there's a larger world acting on itself and them that they can be a part of.
There are some issues that should probably be ironed out beforehand though, like... what does a post look like even? What can a player do. Where? Who cares if the players do somethings and how /why do they care. This will generate content. (might be simplier than I just made it sound)
Build something that isn't solely about short distances to keep FPS up, while keeping in mind that somebody's got to describe it still
. Less limits, perhaps.
Build ships if you wanna/can. Build railways (well... not trains exactly) . Sponsor caravans whatever.
Does that make any sense or ...?
I hope that helped some. Did it?