About the Charizard using Explosion, I think I saw it in Thesis' essay on OT fics, actually. (That's a very lame pun, too. Thesis' essay.)
Actually, there is no real minimum age for the trainer thing (except for the base limit of 10, obvs), but Rachel gets it at 11 instead of 10. That kind of little nudge is fine, right?
You might have to wait a pretty long time for the polished version, though, because I'm planning on releasing it concurrently with the third instalment of Generation 2021. (The third "arc", so to say. It involves a boy and his Rayquaza, and a [****]load of editing to make sure that the story isn't broken. I'm barely 60% of the way through the first one, and that took me a year. So... yeah...)
Also, it was uboa, not eboa? Aw crap.