I understand your pain I was actually up very late or should I say very early trying to beat the butcher level in velvet assassin and I was trying everything downloading cheat engine tables trying to find other trainers for it none of them worked . However their is a very easy work around. just look at this post in the guides section on the steam home page ,
http://steamcommunity.com/app/16720/guides/#scrollTop=0
here is the text from the original
difficulty.cfg
file opened using note pad
[easy]
NPCDamage = 1
PlayerDamage = 1
SearchTime = 1
NoiseRange = 1
PatrolSpeed = 1
SneakSpeed = 1
MorphineTime = 1
[agent]
NPCDamage = 1.2
PlayerDamage = 0.85
SearchTime = 1.5
NoiseRange = 1.2
PatrolSpeed = 1.1
SneakSpeed = 1
MorphineTime = 0.8
Here is my modified file again using note pad
[easy]
NPCDamage = 0
PlayerDamage = 1.2
SearchTime = 1
NoiseRange = 1
PatrolSpeed = 1
SneakSpeed = 1
MorphineTime = 25
[agent]
NPCDamage = 1.2
PlayerDamage = 0.85
SearchTime = 1.5
NoiseRange = 1.2
PatrolSpeed = 1.1
SneakSpeed = 1
MorphineTime = 0.8
All I did was set NPC Damage to zero and they can not kill you I also set morphine time to 25 but used it once and it goes on for to long so I will probably set it back as it is unnecessary .
Just be aware that yes even though you can kill a Nazi shooting at you with his sub machine gun with your knife you will get a lower game ranking for not doing silent kills. but this reduces the game to looking for stuff and the game goes through much faster .
Used paint to make a couple of images to show you where the files are please note some of my files are changed to the note pad symbol becase I opend them with note pad . Links to files also in the guide coments .
http://steamcommunity.com/sharedfiles/filedetails/?id=799378838
http://steamcommunity.com/sharedfiles/filedetails/?id=799380959