My theory is that, just as Einstein demonstrated that forward time causality can only happen at a rate of Distance/C, and that two event separated by that amount of distance/time would appear to be simultaneous to any observer.... I think there might also be a relativistic approach to resolving time travel paradoxes.
My idea is that, when sending information back in time, there's a "one time interaction law" which states that you can never interact with the same event (where an event is defined as a four dimensional location) twice. Hence, if you grandfather conceived your father during a night of hot steamy sex with your grandmother, you're one interaction with that moment in history is already over, and you can't ever travel there again if your goal is to interact with it. (You could watch but.... I would advise against it...... if only for your own sanity sake.)
However, if you want to go talk with a martian who lived on a far away world 10,000 years ago, you can feel free to do so. It's not your own history you are changing. It's someone else's history. (Maybe there are some alien cultures who interact with one another in the other's history, but from their own present..... just imagine how that would pan out..you could end up getting dominated by a culture that is younger than you are.)