The issue with suggestions 1 and 2 above is that people can kill the game without its permission... e.g. disconnecting the network cable or turning their machine off. I'm fine with suggestion 3, but it still doesn't stop someone disconnecting outside the game. I'd also add that the transition between hyperspace and normal space is the most likely time the game crashes, so someone disconnecting whilst being interdicted (coming in from hyperspace) may not be their fault.
Just personally I think that there should be some reward for not logging out to encourage people to play the game as intended, rather than alternative ideas for punishing people if they do. Say... if you're left looking at the insurance after being taken out by another commander then you get some rep and/or materials to show appreciation of your sacrifice. Slight problem with this is that you could see scenarios where people get in their sidewinder and let their friends take them out multiple times... but this would mostly be solved if they just stuck a weekly timer on it so you couldn't get that rep for being killed by the same player again in that time-frame.
Admittedly I'm talking as someone whose seen the insurance screen for my courier 3 times in the last week - courtesy of a wing of Smiling Dog Crew FDLs in Carthage
