Let′s face it, we argue back and forth about how the game should be and we all have our own ideas, many of us want to be so restricted that we feel like Houdini on a bad day, others want so much freedom that the game should feel like a lucid dream where you can do anything! And then we have everything in between. But the question is, considering the possibility of having content that only certain types of characters can access, for example. We could have a guard faction that is if there is any such organization in Skyrim and we ofc have the Dark Brotherhood confirmed, then some would like to be able to do both but others (me included) want there to be a quest in both factions that forces you to choose sides. And we could have skill based things, like dungeons you can only pass through as a thief or a warrior or a mage (mages tend to be jacks of all trades so there could be some magicka draining zones or something alike).
How much of the game would you want to finish in a single playthrough considering such scenarios ?
I chose 51%-60%. To some that may seem a little high considering the criteria you laid out, and although I believe in consequences for your character's in-game choices, I also believe your character should have enough room to maneuver morally and socially within the game, so as to have the oppurtunity to evolve along those tenuous paths that some call 'good' and 'evil'. It simply adds another dimension to character growth, and I sometimes like to inject a momentously pivotal moment of redemption (for my selfish, sinister, devious character) or debasemant (for my altruistic hero) along his/her journey, but I only do it when the timing seems right and the elements of the story come together in a way that seems to sensibly justify such a change.
As for the second part about dungeons only being accesible to certain character types(warriors , mages , theives , etc.), I'm for something like that in moderation, and I think if the radiant story is done properly, we may not get dungeons tailored to our character type, but we'll certainly get side quests designed specifically for the type of character we've been playing up to that point.