Just to clarify, no, body swaps in Elysia are much the same as they are in Yamatai. They're completely free, and available to any one, at any time, with the exception of a certain level of criminal or mentally ill individuals. So unless the character is a pretty major criminal (in which case, they're not going to be allowed in the military), or flat out doesn't want to switch, they can switch at any time.
Now, a couple quick things, before you fix that.
We need both metric and imperial measurements for both height and weight. Not entirely sure why you mixed and matched, but eh.
Past there, I'm going to skip a bunch, since the body swap could change a LOT about those areas.
Just in general on the skills, we are technically still a full part of the SAoY. That means you need the four required skills, even if you started elsewhere. Those would be required just to remain a member of the military. Specifically, you need the required text in Communications, Fighting, and you need to add the Mathematics skill.
Explosives needs to be more specific than that. Just detail it more. What kind of explosives? What kind of uses is he best at? And so on.
Vehicles needs to be clarified and cut back. There just flat out isn't enough time to learn every vehicle, in every faction, of every type. Also, Maintenance would go under the Maintenance and Repair skill, not Vehicles.
Past there, nothing needs to be changed until I see what's altered because of the body.