No blocking is being done by nothing being at the bazaar. There are many other ways to achieve the goals.
All I can really do is reiterate:
The player's goal for his/her PC is to find an item that might be useful. The game could cut to that chase. Or the player could jump through GM-establilshed hoops (whether pre-authored or rolled for) before getting to that outcome.
I don't understand by what criterion you suggest that the first undermines player agency over the content of the shared fiction while the latter affirms it.
No, it's not subsumed within their characters' dramatic needs. If my wife has something important to her that she cares about, it becomes important to me and I care about it. My care doesn't strip it away from her and make it about me. D&D is no different other than the DM is the partner with the players. If I introduce something that the players come to care about, it doesn't become theirs. It becomes a partnered care, just like when I care about something they've established as a important for their character, what they established doesn't become about me.
I don't really follow your point here. What I was saying was a response to [MENTION=29398]Lanefan[/MENTION] contrasting "PC dramatic needs" with "the game/campaign as a whole". My point was that if that stuff is something the players actively care about and want to engage with, then it itself has become (on aspect of) PCs' dramatic needs. (Eg if Lanefan mentions slavery, and the players decide to have their PCs fight in the cause of abolition, then ipso facto abolition has become one of the dramatic needs of these protgaonists.)
Hence it follows from Lanefan's contrasting of it with dramatic needs that it has not taken on such a status; and hence is something primarily of interest to the GM. The players may or may not want to go along with it, but if they do that is not any exercise by them of agency over the content of the shared fiction.
when going down a passageway, an intersection represents a change in the environment that I would alert them to.
This is just your opinion on what is salient. You (and [MENTION=29398]Lanefan[/MENTION]) care about passageways. I find that they very easily become boring, and if there is nothing at stake and the players don't ask about them I'm happy to disregard them. In my Burning Wheel game I will cheerfully resolve an hours-long trek through the catacombs with a single Catacombs-wise check.
If the player wants to know the layout of some particular place for some particular reason, we can get to that level of detail and work something out (most likely along the lines of "I make a Catacombs-wise check to find the six-way intersction I've heard about underneath the cathedral"); but no one is interested in cataloguing every intersectin down there for the sake of it.
I'm not rushing them from place to place
Again with these meaningless metaphors. Narrating "OK, so you go through the door back into the corridor" and "OK, you travel through the Underdark and arrive at the lava-filled cavern the dwarves described to you" are
identical narrativbe processes. Neither leaves out more information than the other, or railroads anyone more than the other. That's a fundamental difference between fiction and reality. In reality, every square inch of every surface someone traverses exerts causal influence over them, and they exert the same over it. But in a fiction, there is only what is narrated. You don't give the players more opportunities for choice by narrting only things that are nearby rather than things that are geographically distant!
I would already have told them about the flagstones on the floor
Do you mention every floor covering in every room? Every road surface? Every species of plant in the wilderness? ("Hang on, that's not normally found in these parts! What animal - or evil druid - spread it to here?")
Every wall surface - stone, brick, plastered, painted, bare, scrubbed, filthy, etc? (Think of the plastered wall in ToH for a concrete example of a module which turns on this.)
To be honest I find that impossible to believe.
I would tell them if the flagstone passage turned into a smooth cave like floor.
I live in a typical urban neighbourhood in a multi-million population industrialised city. Walking 100 m down my street involves passing multiple sorts of road and footpath surfaces (cobblestones, asphalt, concrete) plus various "hatches" (some concrete, some metal) plus heavy metal ramps laid over driveways (that my girls love to jump on so as to make a noise). No GM in any modern or sci-fi game every narrated things in that degree of detail.
I've never been to a mediaeval city (obviously), but I've walked through cities that more closely resemble our fantasy cities than does modern Melbourne (I'm thinking especially Fez, Zanzibar and Nairobi). Street surfaces are sometimes dirt, sometimes paved or cobbled, sometimes muddy. Building are sometimes stone or brick, sometimes timber - or a mix of both. Some are permanent, some at least look more temporary (eg rough-hewn timber bound together with cord). There are balconiies, and shutters of various sorts, and cords running across the streets or between buidlings, etc.
No GM in any fantasy game ever narrated all this stuff when the PCs walk down the street. Yet all of it is
potentially salient. Is it railroading not to do so?
You gave them no opportunity in your example.
<snip>
You gave them no opportunity to tell you that they were stealthy in giant territory.
The problem I have is that if they don't get the "front porch" scene, then unless the players are expected to declare all manner of moves in advance about what might possibly happen, the DM is railroading the players through places by making decisions for the PCs. If they are expected to declare those moves in advance, the game becomes a giant game of chess where you have to stop the momentum of the game so that the players can strategize about every situation they might encounter and give the DM a plan. That wastes a bunch of time on things that the players won't ever encounter.
Are those last sentences based on your experience with "story now" play? Or are they just more conjecture?
If the players want to approach the giants stealthily, they can do so. In a 4e game, the whole trip is probably being resolved as a skill challenge, and if the PCs want to put a group Stealth check in there to try and achieve the result
we see the giants before they see us, they're welcome to. But they don't need me to remind them to do that. They're the ones playing their PCs, and they're the ones who know what they want their PCs to do. They can make these calls if they want.
I would call it a negative characteristic of a GM if they really try to jam the action forward so forcefully at the table that the players never get a word in edgewise to say theses things. I don't think Pemerton would object to that characterization.
This is why I asked [MENTION=23751]Maxperson[/MENTION] if, at his table, the players need permission to speak. In my experience, if the players want their PCs to do something they will say so. Conversely, if they're keen to get from A to B because that's where the action is, it adds nothgin to the play experience for the GM to mention ten different intersctions to fill half-an-hour of the session before we get to B.
In part under the influence of other posters who play more avant-garde games than I do, I've become a big fan of "OK, yep, you did that, but now what about . . .?" - that is, if the players want to make potions or stock up on assault rifles or whatever it is, let's just write it down and knock off the ritual components or credits or whatever it is, but I'm not that interested in the
players using this sort of hemming and hawing as a way of putting off hard choices. Or of seeking in-advance assurances from the GM that, if only they pack the right gear, then everything will turn out how they want. I push them towards "story now" rather than "story already written via the equipment list".
That doesn't mean that there are never hour-long logistics interludes in my 4e game, but I prefer to keep them to a minimum.