These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Also in-story: whatever else Sasuke decides to do with himself or his plot against Itachi, every single person tells him this: DO NOT LISTEN TO OROCHIMARU OR MADARA. EVER.
Jossed: That Obito died and is not Tobi...Lucillia decided to retcon it as Kakashi's being from an Alternate Timeline. If you consider the common time travel logic in that just traveling back, the time travelers of the story had already altered the timeline, this actually makes sense.