Is future sight reading minds or is it actually seeing the future? Or does it vary from user to user?
For example, in Skypeia Enel couldn't future sight Luffy's arms when bounced off a surface, because there was no intent behind their trajectory. So could the same thing be used against Shanks? Could Shanks foresee Usopp's traps attacking him or exploding, if they were put there well in advance?
What about if it's actions performed with pure muscle memory and without conscious decisions? Like ultra instinct? Can he foresee those?
And even if he can read the person's spirit and not just their conscious mind, is 10 seconds even useful in an actual fight? A lot of the actions aren't planned 10 seconds in advance. He could see Kidd attacking the ships in advance, because Kidd was already planning his whole attack. But say if Shanks is standing next to Mihawk and then says "your huge sword is compensating for something" and then Mihawk is like how dare ya punk and attacks him 1 second later, I'm guessing Shanks can't foresee that 10 seconds in advance, because the thought intention only started in Mihawk's mind and spirit 1 second earlier. So he can read a pre-planned attack sequence or can read if Mihawk thinks "if I do Slash A, if during that Shanks does Attack A I'll do Movement A and Slash B to counter it, but if Shanks does Attack B I'll instead do Movement B and Slash C to counter", so basically he can read preplanned contingencies that are already in the user's spirit.