I think you should be able to sleep in order to pass time. Imagine this, you order a sword and the blacksmith tells you that it will take 3 days to make. What do you do? I know I would personally wait in place for 3 days out in the rain and the cold until it’s done. I honestly don’t want to have the option. So I would vote no to waiting but yes to sleeping.
Also with the tiredness bar, I vote on my own thing. If you sleep for 8 hours let’s say, you get a stamina regen buff on 5% or something similar. after 10 hours the buff disappears, then after 5 hours again you get - 10% stamina regen or something similar.
And no to fast travel. If I get the option I will just miss-use it Anyone played Skyrim with the ScenicCarriages mod? Basically you don’t get taken to a screen and ported but rather you sit on the carriage the entire way while the guy “driving?” gives some fun facts about the area etc. You can also be attacked by bandits while on the carriage. Also isn’t the KC: D area pretty small? I don’t think fast travel will be that necessary ^^