BUT I do think MN (and maybe the world in general) is a bit obsessed with ensuring that toddlers/children always follow adult directions to the letter, I don't think that you have to have this dynamic at all. It is possible to differentiate, even from very young (around 3 or so, I would say) between situations where there is room for negotiation, and situations where you have to follow instructions NOW, however, even in the "do it now" situations, you can ALWAYS ask questions later.
Lastly I tend to think that relying on directions in itself can be a bit of a fool's errand - I don't particularly insist on obedience to verbal directions (with two exceptions: Stop/no/freeze I expect to be followed immediately and we can absolutely have a discussion about it even immediately, but you need to stop first THEN we talk) and the situation where I say look: This is a dangerous activity, I need you to do what I say straight away. (This one I do for stuff like cooking, DIY, crafts, maybe water play etc).
If there is some kind of boundary issue outside of these things, particularly safety, I don't even frame it as a direction to be followed or not (other than the previous examples) I would just generally take action - I think this is from the How To Talk books - they call it "Take Action Without Insult" or something like that. So instead of saying "If you hit your brother again I will take away your train set" and then waiting for the child to comply or not and then punish or praise respectively, you just physically go and prevent the hit either by removing the item from child's hand, interrupting aggressor by crouching down to speak to them, picking up the victim, placing yourself between them, blocking the hit, gently taking hold of aggressor child's arm, whatever is safe and appropriate and possible, and combine that with a statement like "NO hitting" or (the more Janet Lansbury) "I won't let you hit your brother."
Everything else is basically open for discussion, and I do try and see their perspective and I do try to take it into account but it is about balancing needs, and I'll happily discuss this with them (if they are old enough to understand this) because I think that is part of helping them learn empathy and not just thinking about themselves. And no, I don't think this does lead them to expect that with every other adult, though some children do seem to find this more difficult to understand and in that case then it's worth talking and explaining about different roles. Because even as adults, usually the degree to which we expect to be given and follow instructions from others varies hugely depending on the relationship and situation anyway.