You have a good point with the charisma thing. 1. How many points do I have left exactly? About the corpse though, 2. would that depend on how rotted the corpse actually is?
Strength: 12
Dexterity: 12/12
Constitution: 12/12
Intelligence: 14/16
Wisdom: 14/16
Charisma: 10
if you don't want to min-max, simply put the points you don't feel like using in the lower ?*/? scores
2. i'm gonna rule that wights simply look like highly pale (actually bloodless, their heart has stopped) people, they can still speak Common after all. The only things they really lose on transformations to Wight status are their experiences (i.e. levels) and freedom (Spawn of the Wight that created them).