This is better. I'd still argue the XO should be a Lt.Col and the CO be a full Colonel but we have three-ringers incharge of some pretty important shit in real life so that's not unrealistic.
If you want Doctors to be Officers then Researchers should remain Civilian and report to the Corporate Liaison.
Mess Sergeant should really be a Sergeant or renamed to Chef/Steward.
Squad Leads should probably be Staff Sergeant again.
CT's being PFC's is hilarious and I love it.
MT's should probably be at least a Corporal.
MPs should be given a rank buff to non-existent.