Yeah, we need abandoned ships and space hulks. I agree with Vorgra's implication that refurbishing one safely should be a non-trivial endeavor, but hacking off bits that look like they work and taking them to your own ship should be easy. Of course, we don't have things like warp demons and genestealers to populate these with. We need to figure out why a ruined ship would be drifting around unclaimed, and hazardous creatures and situations to make claiming it more than a case of "free money!".
Putting hostile aliens on a ship would be easy enough; but my reasoning for why ships would be abandoned is simple: Someone shot up some critical system, and the ship limped/crashed into an orbit. Or the ship was busted up after entering orbit; my feeling is that all combat will occur in/near orbits of larger structures/planets. Think the Andromeda - it was caught in a gravity well and (almost) everyone abandoned ship. Or some idiot captain ran them out of fuel/propellant/energy and they were in orbit in a place where there wasn't any fuel to be had (for the engines, reactors, or the FTL drive), so everyone died a slow, horrible death. Since fuel is a huge majority of the mass of a ship IRL, it's unlikely you're carrying enough to refuel a ship unless it's much smaller than your own (or unless the dev's bend the rules and make it so you don't need to carry 1/2 or more of your ship's mass in fuel; which would be reasonable for orbital maneuvers). Making the ships only appear in areas where fuel is hard to obtain would make it very
difficult to salvage any large ship. Especially if you allow 'radiation damage' to all the critical electronics and maybe even the main reactor/FTL drive.
My question for the depth here is one I've had before -how much are we expecting this game to be an in-depth FPS and how much an in-depth "build-your-own-spaceship" sandbox? We've had lots of discussions about FPS-esque aspects to the game, but I'm not sure that it'll be that
in-depth. If we're lucky, we'll get 'build-your-own-weapons' and transporters for boarding actions. I'd like to see derelicts because they'll add flavor, but making them into a game of their own isn't really likely to happen until way down the road.