actually the easiest and simplest answer is seen in the oldest of games: no saving. think about mega man, the original. 3 lives, and complete the game, or you start ALL OVER. in this day and age of gaming this is not often used but there are games that have these options. try thief with all of it’s modifiers turned on scary face it’s a nightmare, but doable, and you feel a real sense of accomplishment from doing so. even to a degree games like Demons’ Souls have a similar mechanic that once you’re in the level, and you die, you go all the way back.
i’m thinking that a mix of this is probably the best. my favorite (i can’t remember the game off the top of my head) is the limited number of saves and no checkpoints. if you want to go back a save… well, you might lose way more progress than is worth it so you have to deal with the consequences of your actions. in the end any game that has saves in it, whether limited or not, runs the risk of having the player do this.
if you could combine Rogue-like mechanics in a story driven game, then i think maybe that’s the best. you can never have the same encounter twice, and so loading a previous save would count as a death/respawn scenario and so you don’t get the same encounter, you might not even meet the same person… hell, you might not even have the same quest/scenario/objective when you load.
another piece of the argument you bring up: seeing the multiple outcomes. sometimes i like to reload to see how things might have played out differently, then i go back and reload and take my first choice again. this way i can get a taste for the change and if i don’t want to do that during this playthrough i won’t, but i leave that savepoint so i can come back to and experience the new outcome. most of Bethesda’s games can be abused this way. and it really is an abuse, i know it, and yet it IS part of the game design. I also generally do one playthrough that is always pure and no take backs on my choices. this way i feel like i did have a sense of my character in a certain way before i go back and see the various iterations of how the dialogue/story/missions can play out. Deus Ex was a great example where i would smash and kill everything my first run through, then i would explore the area afterwards and find all the vents and secrets and such, so that my ghost playthrough was a little easier. and even during that 2nd run, things were still being discovered. great level design really is crucial for games like that. With KC:D it’s inevitable players will “abuse” saves, and yet it sounds like the AI systems are dynamic enough that they could use the player reloading as a seed for randomness in the towns. i know for my part i’m going to once again play through genuine the first time, but i do like to explore and flex the limits of the design and story.
oh i just remembered, the livestream showed examples of how the dialogue “branches” but in such a way that you can’t go back and get the same dialogue again, like in Skyrim or Oblivion. so while you could reload and go down a different dialogue path, i’m sure each will have it’s pros/cons toward the story and once you do find the choice you want, you’re locked into that choice. the AI is supposed to remember you and so eventually your choices will matter and there’s no take-backs once you’re happy with your choices.