So, I've already pointed out it's a little weird that crews can't go above 2000 from training, but in the academy.
Not big of a deal, but how exactly do troops gain grade points in combat?
I've had a crew swat countless missile salvos from the sky with marvelous 100% efficiency and not gain a single point, and I've had a ship with very strong shields (but honestly not much else) gain 84% by taking Missiles to the face in a single battle, without even trying to engage them (aside from the CIWS, which had 0% hit chance despite ECCM10 versus ecm 100 on the missiles, an eccm which is perfectly sufficient on any other weapon).
Is it only by taking damage?
In that case, I would probably level up ships by sending them to a low tech NPR and taking a few salvos before recharging....