Ooer, you have some pretty cool ideas there. I think I'm gonna go for a male character, and yeah, say that his family's been serving the crown for a couple generations. I was thinking of doing that anyway xP
I think we should go with them having known each other since they were children, but aside from playing around and knowing each other, they wouldn't have had much of a 'professional' relationship up until he withdrew from politics and whatnot, at which point the king/queen decided to give him a... protector, I think we could call it? Also, his mother died? I thought his mother would've been Queen Claire? Or did I miss something?
Oh, and as for his Pokémon, I was thinking of letting him have a Druddigon. Might be a bit... powerful, but I'unno, what do you think?