Yes it does, don't kid yourself.
It doesn't actually. There is no world, just the DM's imagination. You can get immersed in that world all you want, it doesn't change the reality you are essentially directing a play and the freedom that entails.
Yeah and all of these can happen off screen and the PC only need to deal with the consequence. If an action isn't taken in front of the PCs it doesn't matter how it happens, only the consequences do. A monster with stats for activity that doesn't involve the PC is a waste of space on a page. You're the DM, just make them reanimate the dead or spread a disease in town if its something one can do in your world. The particulars don't need to be in the stat block because they don't matter. No matter how good the Orc is at playing the banjo, I don't need to know his Performance skill score because it won't come up. I can just say 'As you approach the Orc, you can hear him playing the banjo beautifully'.
I think, ideally, players shouldn't realize they're doing a skill challenge at all. You just present them with obstacles, let them propose solutions and you narrate the resolution while keeping track of their success.