But...
This brings me to another point...
I think that some skills should bleed over to one another when they are increased. For example, for every 10 First Aid you get 1 Doctor (until you reach 100 in First Aid, after that point Doctor won't be increased unless you put points into it).
So Persuasion, Deception and even Barter? They'd all bleed into one another that way. If you're great at persuading people chances are you got what it takes to tell a little lie too. So if you start with 0 in all skills and raise Persuasion and Barter to 100 then Deception will have increased by 20.