Dang the princess really is starting off as quite annoyingly ignorant. Also, whatever relationship develops between them as kids, it is naturally going to be flawed if he is by her side as a servant. Relationships with unequal power balance are proven through sociological studies to never work out, for pretty obvious reasons. I would not at all be surprised if Latio was involved with the destruction of her kingdom, but of course, this is a romance story so there is definitely going to be more to it!