If you must have it noninteractive, I think the best way to do it would be to have some sort of magical force field or something created by the Veiled Woman, just so your lack of options has some kind of in-game justification.
And speaking of railroading, why do I not have the option of telling that guy in the estate "I'm a Keeper of the Holy Order, and you will give me the Black Stone or else"? I was invested with great authority by the Order yet at a crucial moment in the plot I cannot use my authority to get the Order what it needs. Really "a sandbox like Skyrim" isn't what I want, it's more like Fallout New Vegas, where the quests account for several playstyles and carefully hide their railroading so you don't notice it (to the point where there is only one essential character in the entire game, and it's a robot). Don't want to hear Caesar explain the principles of Hegelian dialectics to you? Just shoot him! You're probably going to die unless you're at the level cap and brought backup but that's your problem.
(yes, I'd be that guy where, if you were doing tabletop D&D or something, I would call out "roll for initiative" in the middle of the villain's grand speech.)
The mechanics that Enderal is built around are designed to facilitate player agency. The systems of Skyrim push players inexorably to free-form exploration and expressing themselves through gameplay and dialogue options. Enderal's tendency to railroad the player through cinematic sequences grinds against its own mechanics. I feel like the project could have benefited from adapting Obsidian's strategy of presenting quests more as problems to solve with varying options depending on your character's skills, abilities, and alliances than linear sequences of events, since the basic gameplay loop of Skyrim is what it is and no mod can fundamentally alter it. Gothic II doesn't run on my computer so I haven't played your biggest inspiration, but I imagine it is probably a far more linear game with very different mechanics from Skyrim.
Example: in the Dal'Geyss estate, I see several alternate ways to complete the quest if the game would allow it: use the authority of a Keeper of the Holy Order to extort I mean requisition the information from him, follow rumors heard around town about him until you get to something incriminating, use psionics to screw up his mind, create some ruse with rhetoric to lead him to a place where you can beat him up in privacy, or if all you can do is hit things with other things, just storm in, trash the place, beat him within an inch of his life, and deal with whatever consequences happen. Also, since Dal'Geyss warned me not to double-cross him, I now desperately want to double-cross him just to see what happens.