here's a simple paradox, if queen lene was kidnapped and killed, that being done starts the event where marle vanished right? wrong!!! because if she vanished then chrono whouldnt have known her and she would have vanished from memories, but the mere fact that marle exist, means that the queen shouldnt have died on the first place.......so why did marle vanish, if the queen didnt die??why would they go and save her??
another paradox is the future, we all know that it is essential for chrono to go to the future in order to know what happen and defeat lavos right? but when they defeated him, then they shouldnt have met robot in the ruins in the future..those informations that they have wouldnt have been available when they go there because they already defeated lavos....everything should have changed, the future would have been pleasant, their memories should have changed and if that happened why would they go and defeat lavos on the first place......
the thing that makes the time paradox invalid in the game is their memories...if something change in the past it would have affected their memories which if it did, then the time paradox would have happened......
again its paradox of time.........it will be diffrent if they are not actualy traveling through time and have been traveling in dimentions just like CC......then that would have been a whole new diffrent thing...then each timeline would have been a dimention, doesnt make sense due to the sun/moon stone incident......