So as have been pointed out many times, Baldur's Gate evil parties have little to no advantages compared to good parties.
I propose a new feature which realistically fixes this problem. Have you ever wondered about the different handling of justice between a lone criminal thief versus organised mafia like organisations? Real professionalised gangs around the world obviously are widely respected and feared, even among the police. I think we need a mod for Baldur's Gate which resembles this. A check could be made when a player commits a crime
Number of party members
These factors all contribute to an outcome which is also based on the seriousness of the crime. If a full party of lvl 5 characters with a reputation of 5 and a high charisma fail a pick pocket, the watchers/guards will not turn hostile. Instead they will try to talk to the PC and tell him to "Please try to behave/stay out of trouble". Now if that same party kills a civilian the guards will again try to talk to the PC this time with a dialog and a less forgiving sentiment.
Here the player can choose:
1. Draw steel!
2. (Based on the above 4 factors) "Do you know who I am? CHARNAME, so you better keep your mouth shut and mind your own business".
3. Bribe the guard. (based on 4 factors)
Option 2 and 3 can lead to success or failure, but this way an evil party has a chance to be feared and respected instead of being treated like wild animals.
Think about it? Would you risk your life against 6 hardened criminals when you were just a simple guard in a cheap leather armor at the Friendly Arm Inn gate?
(Pathetic groups of 2-4 characters, lvl 1-2, with low charisma will, however, fail in every situation and be attacked no matter what.)
This design does NOT mean that the player can do whatever he/she likes, cause the Flaming Fist FBI-wannabe group will still turn up and so will the hired assasssins if the rep goes too low and the killing too high. Also it only affects guards (and perhaps a few other selected npcs), while if you start killing people near some mage that mage will still show you no mercy.