CHA1 with no social skills would equate, in my mind, to a very socially inept character.
Since the skills are neatly grouped into categories, I'll go through them one by one with the assumption that the character has zero ratings in each and a Charisma of 1. Keep in mind these are all my interpretations of fluff, and not crunch.
Con governs the ability to manipulate or fool an NPC during a social encounter. This skill covers a range of confidence games as well as the principles behind those cons
Whether by virtue or simple inability, the character cannot tell a believable lie to save his life (literally!). Except in circumstances where the character is in possession of a really good disguise and/or convincing evidence, and in a situation where the target of the Con attempt doesn't have the time to consider what's being said and it isn't detrimental to the target, the character will be nearly completely unable to come up with even a half-decent white lie.
Etiquette represents the level of understanding and awareness of proper social rituals. The skill works as a sort of social version of Sneak, allowing you to move unimpeded through various social situations. Etiquette also serves as a social safety net in case a player botches a social situation in a way a skilled character would not.
This is the kind of character who, without thinking, might babble in excited interest when he sees that the Johnson has the latest piece of [weapon/augmentation/fashion] in his possession/on his person, or the kind of guy who'll ask the Mafioso muscle what his problem is when the Mafioso looks in his direction. Alternatively, it's the kind of person who never meets your eyes when talking to you, or who always wears inappropriate clothing, or who fails to adhere to table manners or "common decency". It might also be the kind of person who flat out refuses to do a job "because the pay ain't good 'nough", or who doesn't know any of the customs of the people he's talking to and ends up insulting their mothers through some slight miscommunication. He's not necessarily as suicidally offensive as the uncouth character can be, but he's not far from it.
Impersonation is the ability to assume the identity of another person, including voice and physical mannerisms. The skill is limited by the physical abilities of the character. A dwarf might be able to impersonate a troll over a commlink, but the illusion shatters when he is face to face with his target.
To me, this is nearly ever single Christopher Walken or Arnold Schwarzenegger impressionist out there, and would in this case be represented by characters who can't do any accents or change in intonation at all, and who comes across as wooden when trying to be someone they're not. This is similar to Performance, below, at least to my mind, but applies more on a one-to-one basis as opposed to the one-to-many of a stage actor.
Instruction governs the ability to teach people. The skill level helps determine how comfortable the instructor is delivering new material as well as how complex of a skill may be taught.
Have you ever had a teacher who just couldn't pass along knowledge? This is the guy who knows the subject matter but can't seem to understand how to impart knowledge. It's the advanced math teacher who blames his students for "not understanding" when he explains a subject matter the basic math students haven't got the basis to comprehend.
Intimidation is about creating the impression that you are more menacing than another person in order to get them to do what you want.
This is the punk who thinks he's hard, but who comes across as nothing but. It's
the opposite of Vinnie Jones in Snatch, or the thug with the "knife" who threatens Crocodile Dundee, or pretty much everyone who's lived a sheltered life amongst the rich coming up against a hardened criminal. Anyone with a shred of backbone on their own will be able to see through the posturing.
Leadership is the ability to direct and motivate others. It’s like Con, except rather than using deception you’re using a position of authority. This skill is especially helpful in situations where the will of a teammate is shaken or someone is being asked to do something uncomfortable.
This is the POS night-manager that some of us have had to deal with, who has no management skills but thinks he's the business. It's the officer who has all the training in the world, but no way of applying it in combat. It's the masses of people who, when faced with an emergency, stand still and watch others take action. They are the opposite of the civilians, firemen, and policemen who ran towards the towers in New York when that ugly business took place.
Negotiation governs a character’s ability to apply their charisma, tactics, and knowledge of situational psychology in order to create a better position when making deals.
This is the person who doesn't know what he's got, be it skills, items of worth, or money, and who demands too much or too little for what he has. It's the people with low self esteem or that fear confrontation so much that they cave to any argument or debate that opposes their point of view. These people are the targets of scams like used car hustlers, door-to-door salesmen selling doors, or real-estate agencies selling property on Mars.
This skill governs the ability to execute a performing art. Performance is to the arts what Artisan is to craft. The performer uses her skill to entertain or even captivate an audience.
See the Impersonation tab above. These are the people who can't remember their lines, or who cannot tell a joke to save their lives (again, literally!). It's the people with no rhythm trying to play percussion, or the ones who have no concept of pitch who go on American Idol.
Note that social modifiers can make even a socially inept character at least mediocre.
With regards to intimidation, someone with 0 dice can get up to [Street Cred] dice for being known, 3 for being physically imposing, another 2 for outnumbering the target, and another 2 each for wielding a weapon or causing the target pain, and another dice if the target is drunk. Going from 0 to 10+ dice isn't bad; of course, if using all of the above the target could be considered either Hostile (-3) or Enemy (-4) at this point, and depending on what you're trying to intimidate the target to do you could be racking up negative dice modifiers of up to -4 for a total of -8 dice pool modifier, bringing you back down to 2+.
That's quite enough for me, I think... Hope it helps.