In my humble opinion if you choose to log out with aggression from another player in open mode, you should be banned at least a week from open. Clearly you don't want to play in open with another human beings, and in this way the game will help you to choose the mode you really like.
Tricky... What happens if your PC simply shuts down? eg: Powercut? Or an internet hiccup?
And more importantly, while the game still isn't enforcing a Crime a Punishment system/mechanic anywhere near at an adequate level, I'm actually for people "pulling the plug"...
For example, where you get Wings of griefers at a (CG) station doing nothing more destroying CMDRs (traders) flying towards/out of the station! Not for one second should these individuals be rewarded with the "grief" they're after due to the game's lack of mechanics. eg: Ship after ship being attacked & destroyed just kiolmeters from a station by Wanted individuals, and the station does? Nothing! The local forces do? Nothing! And said individuals then even fly into the station to restock ready for more of the same.
So, while the game mechanics allow rediculous antics (griefing) like this to happen, I for one don't like the idea of the game helping them... I see the importance of players having a way out from mindless griefing
(so as not to reward them for it) as more important than, for example, my risk of losing a "victim" while Pirating.
Once the game has started addressing this sort of stuff though, and griefing isn't ignored by the game, then:-
1) If you're doing a controlled exit from the game (with a 15 second countdown) - Show this countdown to all players in your instance.
2) Maybe extend the controlled countdown from 15 to 20-30 seconds?
3) If you are in a combat situation (ie: exiting would result in a 15 second countdown) and the game does an uncontrolled exit, on the next startup of the game, warn the player. If this happens regularly (quantity/time frame to be determined) restrict access to OPEN for increasing periods of time.
Ultimately the game should promote (offer) consensual PvP, and deter (mindless?) unwanted CMDR destruction by another CMDR. At the moment it's doing neither of these!