This is how I see charisma acting with the other attributes, now, allow me to baseline the other attributes.
Strength- higher it is, the stronger you are, the more visibly stronger you are,
Dexterity- Lithe, quick, agile, higher it is, the higher those attributes, the more it appear to be.
Intelligence- Diction, smarts, stratagy, plot, scheme. Magic Wisdom- Common sense, intuition, gods be loved. An air of intelligent arrogance
Consitution- No visible attributes apply,unless you think being covered in scar tissue applies. Ability to resist poison and disease, and how much ya can resist having ya head bashed in.
Charisma-(the attribute that dms love the most) Range from scars, to being God-like Beautiful. To being socialbly unacceptable to Mr.Popularity.
Now, When Charisma and strength apply to each other, the person is strong, but he appears dangerous as well. For example: A charisma 6 half orc meanders down the street, he has 20 strength, and you realize he can bash your head in if he wants. okay, who cares? he's an ugly brute with only his axe to intimidate you. Now, an elven barbarian Walks down the street with 18 strength and 14 charisma. You realize he is very, very, very dangerous. You might want to stay out of his way, you might want to enlist him to bash some people. His air of hidden rage makes this fellow potent and threatening. And when he threatens to kill you, you are likely believe he will carry through.
Dexterity and CHarisma. Dexterity alone makes the fellow lithe but rather unattractive, he might cause trouble, and be a nuisance and purposely fail to mention that spike trap in front of you.... Charisma and Dexterity makes you realize he can be of use on your mission, and you suppose he can get along with your group, (supposedly) without causing a ruckus. He will be very useful, you decide to hire her.
Charisma and Constitution have no visible interaction with each other on my book. But mentally this fellow is tough, he can be tortured and not let out a sound, he can be beaten whipped, and so on, and his resolve remains the same. (Note this is the High con and charisma) to him, such pain is nothing compared with what he endured in the past, or so he tells himself.
Charisma and Intelligence- Intelligence alone makes a fellow smart, now add some charm, and you have a leader. This fellow is listened to when he speaks, he can receive a standing ovation even if he believes it was a total disaster, (Depends on other charctors). He usually has friends with key political figures, and can hide his emotions well. This fellow can give good advice, and councel well.
Charisma and Wisdom- The preacher giving a speech might not be listened to because of no charisma. But the Charismatic preacher will be having hoard of followers. At the same time, this fellow has plenty of common sense. When he says it is foolish and folley to continue, he is usually right, and his fellows heed his advice.
Low charisma anything/ this fellow might be smart, wise, strong, Tough, lithe, but what makes him different? the guy smells bad, or has a ruinous personality. If he is a cleric, you don't want anything from his god. if he is a druid, the wizard might be so contemptious he might refuse to even travel with the druid. The guy is shy, or is so forward he is very rude. he has no friends, and doesn't fit in with society. He won't lead, or if he tries to, his group more often than not falls apart, or begins to differ to another person. Nobody will listen to him, he is a nuisance to soceity and is to be done away with. The fact is, he doesn't even exist, and only the kindest soul will ven notice him. No one cares about him, only family.
How Low charisma Effects race. ((Might be in Dispute with others)) a 6 charisma half orc will not be seen as a person, only a meat grinder to be used till he falls apart. A 6 charisma dwarf has no honor (Or appears to have none). He is only a living shield for the rest of the group not worth notice for the occasional praise of his skill. A 8 charisma elf might as well be so shy/arrogant he won't/will do anything that will make others notice him, he believes, BELIEVES that he isn't/is worthy for the "Mighty" to notice him. a 8 charisma Halfling lacks any curiousity or wanderlust, he might as well be enigmatic for the all the inspiration in him. Why, you wonder why he even bothers moving from his chair. An 8 Charisma human is the beggar of Soceity, has no ambition to drive him forward. The only reason he moves is to make gold, and even then, he wonders why he even bothers. An 8 charisma gnome dislikes soceity, he will lock himself in a room to discover some new spell, and keep it to himself. Design a new animatron, and keep it to himself, he is greedy, and does everything possible to make sure no one ever heard of him. An 8 Charisma half elf is so shy she won't even go out in public.
In other words- No charisma is quite ruinous to the entire charctor concept.
End of Rant. I am aware of some disputes, and I would like to note that I made an example of High charisma/other high attributes only. I did not list low charima penalties on other attributes. And I am also aware of this applying to a few charctors, but Ithink this is a baseline assessment.
And on the races, I was merely using examples.