So to establish a ground for what is to come I state that reality is purely subjective.
This leads way to all sorts of potential workings but I'll simply be focusing on one, and that is time travel.
Whether this is possible or not isn't yet relevant, what is however is our relationship with time. Our consciousness travels in the "present" which is a variable fixed at a given rate slightly faster than the rate at which time flows and grows. Thus time travel is simply fixing yourself to a point in time and pushing or pulling yourself toward that point, which involves your mind releasing its grip on the current time which can prove quite difficult. Even so in this new time you're merely an observer, interaction with the time requires a higher state of transience into the 5th dimension which is likely significantly harder than your 4th dimensional travel at this point.
According to popular theory causality can work in reverse, which leads way to spiral factor. The idea goes that there's effectively 3 primary timelines with many subsequent timelines, and lines are constantly merging and splitting. Before you insist on the conservation of energy I'd like to point out you have to first establish a fixed number on the amount of energy in existence first, and subsequently prove that energy is not being moved around with the creation and destruction of these timelines, which are likely more like instances of the originals than duplicates. Moving on, events in timelines form bubbles which work backwards and forwards to ensure that they do in fact happen and in order to then change an event you'd have to go as far back as its bubble reaches. The bigger and more significant the event the larger the bubble created. Intersections of timelines generally involve significant events, it's likely that something like WW2 would've been an intersection of the primary timelines of earth. The bubble created from that event would likely stretch out far beyond even right now, and the outer edge of other events such as 9/11 that might align with that are likely also merging points of other timelines in addition to the central merging at the event.
Paradoxes do not exist as the process isn't necessarily isolating an individual from the timeline but merely relocating 4th dimensional coordinates and thus preserving a continued state of existence in a new timeline or alternate pre existing timeline, assuming that you've achieved 5th dimensional properties necessary to cause a theoretical paradox to begin with.
I'm aware of many large and gaping holes in the idea, but that's all it is, a random thought. A different perspective on one possible idea. I hope that it encourages thought at least.