Sorry for the delay, I had a bit of a family emergency.
Anyway, I don't know much about the Separa`Shan since they're one of those minor Yamataian races, but I believe it should be acceptable species-wise...though it maybe tough on him being with a bunch of heavy gravity worlders.
History wise, it's pretty standard for a new character, not much to define him until RP. However, there's real no explanation for why he decided on the Abwehran Foreign Service.
Skill-wise, he's pretty unique. He fills the archetype of combat-scientist and he even has a few weaknesses (lackluster firearms training) to give him some RP appeal.
Though I am curious as to how a Yuan ti-like creature could learn how to pilot a combat space craft. Mostly because since most designs are based upon conventional craft, which require foot pedals.
Either way, I think he's pretty good. A little more fleshing out history wise for his reasoning and I think he'll be good to go.
He has my approval, but I'd still like another character mod to go over him just in case I missed anything.