I don't think she really cares about romance and i don’t think theres any indication that her zealotry affects her perception on it really, and if taking a look at Serenity modus operandi seduction is probably a legitimate tatic used by the order. Though it should be noted that it's not that hard to hate Emiya, just look at Gil.
Anyway if were talking about battles then Emiya since BA single mindedness of her devotion leaves her open to manipulation which is one of Emiya's specialities.