Hide electrical for future TV outlet
Leaving unconnected wire in the wall will not happen.

I think option 3 is the best: install an outlet in an appropriate stud bay at standard floor height. Then when you know where the TV will hang, you can just add another outlet above at the appropriate height, and wire it in to the outlet below.

Left-right placement doesn't matter too much, if that is a difficult decision now. Even if you get it wrong and you end up needing the outlet in a different stud bay, it's only a small drywall patch or two to work around that error.