The choices are greyed out because you lack something, in the case of the mind control you need the spell, which for now is locked behind Elise's route but in the next patch, everyone will get it no matter their choices, as for Ophelia & Mine, it may be because you lack a point of relationship with one of them, of course even if those options are greyed out it doesn't mean that you won't get an ending that you want or that they're lost for your save file, don't worry about it !