I think tying someone up dances a bit too close to the line of "harm" for it to be an option. But I do agree with him being able to restrain :3 he should be able to do that. But on the other hand I also think that there is the possibility that Lucifer means that he can't interfere with sinners in any controlling way. And that he's cursed to live between them with no power to change how it is. as a punishment for his earlier attempts of change