Regarding sleeping in dangerous areas:
Something I don't recall seeing implemented in CRPG's is the posting of guards/sentries. I think it might be interesting to be able to specify which party members are keeping watch or sleeping and when and to have that affect the possibility/severity of potential night time inturruptions.
For example, during a particular 'watch' in a forrested area characters with woodland survival related skills or rural backgrounds would have a better chance of detecting possible attackers before they attack and be able to rouse the party. Conversely, in an interior/dungeon area those with rogue/thief abilities or more urban backgrounds might have a similar advantage. However, if the character on watch is lacking the appropriate skills or otherwise 'out of their element' perhaps they would face a penalty. And perhaps magic users (or any other 'class') must have a certain number of uninteruppted hours of sleep to recharge their abilities. This could add an entirely new and interesting tactical aspect to character rest periods and also make the use of 'safe houses' or inns even more attractive as all party members could have a much greater (though not necessarily guaranteed) chance of an uninterrupted night to fully recharge.