Not IN Starfleet and everyone knows the Orion Women ran everything that was in the Enterprise series.
I'm such a Trekkie.
For characters keep it simple.
Rank: Check with me but the Captain is rank Commander and the First Officer Lt. Commander, any head of a department Lt.
Oh the Emergency Rescue Team Specialist oversees the rescue operations and would work with the other departments and people trained in things like any rescue person might do in the modern world, just well have more tools. Its a rather key position on a ship like this.