The depth that could be added to Eve with the addition of crews... man, I don't even want to start thinking about it.
Shit too late.
Imagine if they were an almost-living-breathing type of simulated entity. Something you loaded onto a ship by browsing a 'crew roster' or something at stations. Essentially represented by another set of fitting slots, but with regular Sim-City-esque feedback from the peons.
Get into a battle? Sustain casualties. It's obvious, but what consequence could these casualties have?
Crew morale plummets, affecting modules by a 3-5% malus. Or perhaps you receive a reputation as a capsuleer who doesn't care about his crew's survival - leaving you unable to fully staff that battleship you just replaced via insurance. Want to be a capital pilot? Good luck finding a crew if you've maltreated your smaller ship complements. If you keep getting blown up, good luck operating anything bigger than a destroyer.
How to minimize casualties? Upgrade the crew, purchase a medical staff. Morale increases, and more crew are willing to sign aboard. Got yourself a shitty cook, killing crew morale with his Roasted Fedo Anus Tartare? Hire a five-star Gallente master chef and watch crew performance improve. Commanding an Amarr ship? Best make sure the chapel is up to Theology Council standards, so the faithful have a place to bend knee. Commanding a Gallente ship? EVERY WALL IS STUDDED WITH PNEUMATIC COCKS, ALWAYS ALWAYS THRUSTING. Crew morale skyrockets! A Caldari vessel? Gotta have gambling facilities for the officers! A Minmatar ship? I don't know, just fumigate the fucking thing every now and then, and everyone's happy at not having fleas.
Crew is one thing - what about specialists? Why mash the 'scan' button on your d-scanner every 3 seconds, when you can enlist a sensors/sigint officer to give you a prompt heads-up if combat probes appear in scan range, or if a giant fleet of kill-crazed motherfuckers is about to descend upon you. Or alternately, how about crews with different risk tolerance levels? Hire an empire crew and try to take them into a wormhole? you'll find yourself facing a mutiny with modules offlining at random, at least until you replace them with a more grizzled and experienced crew.
/brainstorm