I find that there are discrepencies between world save and character save. Logged in or not, every 15 minutes the whole game should save. Map and characters.
This means that, logging off will offer no protection from server crash, but it will garantee that your character does not lose hours of hard work, It also means that you wont lose important items from server crash, you merely revert to where both were, at longest, 15 minutes prior.
This would create a more balanced gameplay, and prevent "duplicate items, or "lost" items from server crash..
OH!, restarting a server should autosave it, everything. Characters aswell, I notice when I get popups in game, the game world doesnt save, it reverts, and it's a real pain.