I have a theory on the results of time travel

I was watching the episode of "The Universe" on wormholes, and they kept referring to a wormhole being used for time travel. Now whether or not it can be done, I have no clue, but I have a concern that I'm not sure if has been touched before. Many theories have come up regarding this, but I think this one may have eluded everybody.

Now the problem that has touched time travel, is that history and future events can be changed if the traveler can interact with the time they travel to. Some scientists claim that if you cannot interact with the past, you cannot change the future. or vice versa.

Now here's my theory/concern. Time travel will change the past future, regardless of interaction. It's been said, that the winners write history. Even if you can't interact, you can still change history, or change the future. It's the fly on the wall scenario. Let's say you travel back to the time of DaVinci. You can't interact with him, or anybody from that time, but you can see everything. Now you see him making the plans for the flying machine, but he leaves something out. Now from that point on, nobody knew that it was left out, except you, because you saw it happen. You come back to the present, and you can now build the flying machine better than it's ever been built, because you know that.

Maybe a bad example. Here's a more likely one. You were adopted, but you didn't know it. You go back to the time when you were born, and find out that maybe you were the illegitemate child of maybe a Rockafeller. You're entitled a life of riches, but because you were born to a mother outside of the family, you are immediately put out for adoption. You are then adopted to a somewhat less than successful family, and spend your life poor, working jobs like McDonalds, and car washes. If you were there to see that, regardless of being able to change it at that time, you come back to the present time with that knowledge. Can you really hide your feelings when you know you could have been rich and potentially powerful? Now you've altered the future based on what you've seen in the past.

Future scenario. You travel to say, the year 3k. You find out that somebody has discovered an unlimited free energy. You take that knowledge back with you nearly and entire century and use it. Now more than 90 years earlier, you have "discovered" free energy. You look at the enviromental benefits, and you decide to release that information to the world. You just made the future come, 90 years too soon.

Am I off base? Maybe, but I think regardless of whether we can change the past or the future when we travel to it, we will still change the future because we saw it. If you were the fly on the wall when GWB made decided to invade Iraq for oil, but the press told the world it was about WMD's. How would you use that information?

Wormholes happen often when stars die and become black holes. That is how much energy it takes to form one. So we are nowhere close to creating one.