Just in case inspiration can somehow be drawn from my vague ramblings, thought I'd share my ideas with you. Feel free to ignore; it's your effort and time to manage after all.

First, I was thinking of a mod concept: encounters and interactions that require crew but can give a reward. Example, you find a wounded traveler. If you have a medic with you, you can heal him, he drops a reward and beams away. Otherwise he just complains he doesn't feel well.

Other examples:

Anomaly investigation for chemists and other science crew: drops materials like bio samples, eyeballs, ect if you have a chemist to help you investigate.

Suspicious Stranger: Flees, dropping contraband if you have a soldier.

Wreck: you can extract some components with a mechanic or engineer present.

Old lady: Rewards you if you have a janitor. However, the janitor beams away with her to help clean her place up so you have to revisit your ship to re-up the janitor.

Now for some suggestions more relevant to this mod:

-Geologist: improves mining power. Puts out occasional pulses to find ore.

-Environmentalist: provides free EPP effects while alive. Risky, but can free up a slot.

-Survivalist: provides occasional nutrition in the field.

-Quartermaster: would take some work, but lets you browse through all your containers on your ship from a menu.

Navigator: can be asked to find an unexplored planet of a type. I.E. I want an unexplored system with a desert planet nearby.

Fabricator: Halves craft time on your ship. Craft from in-ship storage?

Architect: Boosts max block placement range greatly.

Red-shirt Ghost: Ethereal, provides weak light, can't be killed.

Botanist: doubles plant growth rate on ship.

Cartographer: Minimap? lol. A bit too ambitious for a crew mod perhaps.

Explorer: Provides strong light and throws flares at the player periodically.

Tamer: Brings a random pet for combat support and improves the capture HP threshold.

Mechwright: Boosts starting mech energy in space battles.

Drone tech: Deploys a drone, fights with a pistol. (could be a engineer modification)

Archaeologist: Gives all fossils a feint glow.

Officer: Uses glue spray and stun bombs from peacekeeper expansion. Non-lethal cc.

Portal Tech: lets you beam up whenever while alive.

Hunter: Improves mob spawn rate and gives a better chance of hunting loot even when not using hunting gear.

Hiker: more of a walking container than anything.

Morph enthusiast: follows you in a morph ball. Can't fight.

Soldier variants:

Outlaw change: bandits are now passive until harmed. Uses heavy weapons.

Soldier: vanilla is a fine flavor.

Grenadier: uses explosives. High damage output.

Guard: High health pool, shield

Ninja: uses thrown weapons. High speed, jump and energy. Wall-climb tech?

Sentry: weak fighter.

Commander: summons two sentries in combat.