I would like to see FD expand on the current reputation system.
Have a seperate pirate faction equivalent to the pilots federation.
The pilots federation does not take kindly to killing its (clean) members outside of warzones so if you KILL more than say 2 clean CMDRs in *both* a (can be tweaked) 24hrs game time / say 2 weeks real time you get kicked from the pilots federation.
This then has a cool down period of say another 24hrs gametime/ 2 weeks realtime at which point you can take on a mission and on successfully completing it you are back "in" again.... but if you instigate a fight and kill another clean pilots federation member the count resets.
I would suggest you do not lose your pilots federation stats on being kicked, but when not a member they no longer increase.
if you are scanned in any space station at this point you will be hostile and denied docking and you do not have insurance so you have to pay fully for a new ship.
BUT
also there is a Pirates faction which you can join. you can be a member of this and get new ships on ship destruction here. generally they are lower spec and not necessarily the same ship you lost, but there is no cost, it is just given to you and is based on your rep and what happens to have been stolen recently.
pirates equally do not like blatant murder but they are more lenient than the pilots federation - say 6 kills in 24hrs / 2 weeks game time (pilots federation or pirate faction members only, no one cares about low life AI's

) due to the increased risk of accidental ship destruction before getting kicked.
obviously you get warned as you are getting close to being kicked so you can adjust play style.
the trick here is, you CAN actually be a member of both, and if you are will mean certain unique missions as a double agent for one side or the other.
psychos who kill indiscriminately will be ousted from both and therefore live a hard life on the edge of space, where they have to sneak every where they go and have no insurance.
The only way this can be wiped is to not kill any player for a set amount of time before again getting a mission to rejoin either the pilots federation or the pirate faction.
this makes it not really a viable career mode, BUT it IS possible, which is kind of exactly the sort of thing David Braben said it would be.. Player killers claim they want hairs on neck excitement where they risk it all..... well this would give it.
So a player can carry on playing if they are banned from both, they could still fight in warzones, but with the added risk if any human player scans them and they show up as serial killer and risk being attacked.