I also think you're greatly overestimating the amount of control he has over what memories he sees. They just showed us with his trip with Zeke how hit-and-miss the process is. And there's absolutely zero indication that he can actually sift through possible futures like Dr. Strange.
Unless there is no path where he wins.
If someone slips in and kills him while he's convening with the Coordinate or whatever, all he might know is "My memories stop here."
Agreed. We don't even know if he can see he can actually see his own future memories, or only those of other Attack Titans.