Just a word of advice. Designing in ''emotional'' behaviour has to be done very carefully. (I view it as just another layer to the logic behind a character personally, but call it what you will).

Your audience (the players) are in the game because games are fun and the escapism offered is wonderful. Some games will indeed be benefitted by ''more realistic'' behaviours and responses to the players actions.

However, if in an rpg the player misses out on some key information because a game character is in too bad a mood to explain something, then despite the ''realism'' of the event, the player has lost out.

There are other circumstances in which negative consequences could result from ''emotional behaviour''. Basically, I think a widespread design of emotions into game characters could actually be a disaster from the game play perspective.

Use emotions sparingly and thoughtfully, and they will have a greater (and generally more beneficial) impact on the player.

Woop

Oh, Jesus that would take time!!! Think about after creating game you''ll have to spend rest of your life while adding sentences and actions which are base on your characters charisma/appearance/day/week/month/season or other "emotional" attributes!! Simplier version would be cool like something which generates quests random like putting words and code together:
"Go","Get", "the","carrot", "is","trouble", "needs", "Sue"
"woods", "and", "lives"

random1(or "feeling")

Go get the carrot from the woods

random2(or "feeling")

Sue needs carrot, she lives in woods

random 3
Sue is in trouble, get carrot for her


In case 1 PC(personal character)he/she goes to the woods and fights agains ogres or nasty dwarfs he find the carrot from the body of dead guy and gets the carrot back to the elder who gaved quest.
PC karma +1
PC finds new crossbow and healing potion
PC gains level

I hope you got the point