He's good to go, except as an AFFS character, he'd be enrolled in NAIS, not the Nagelring. The Davions are actually more egalitarian about who enrolls in their academies anyway; the Lyrans have a much more entrenched culture of favoritism.

addendum: And a Phoenix Hawk is a very good choice. The lights and mediums should be maneuverable. I'll also mention that seeing as these are testbed mechs, you can have them extensively modified as you see fit. Considering the sort of enemies the characters will be dealing with, I think that's fair.