Most table top RPGs in my experience are built with a PvE experience in mind. Sure, you can easily enough turn the rules that govern combat between PCs and NPCs for a PC vs PC fight, but the system itself isn't made with that in mind even if it is capable. The only proof I have for this theory though is the way that social rules work, taking something that is composed of shades of grey and turning it into a simple black or white affair.
Now, granted, part of this is simply a limitation of the medium. Conflict is generally done in games via combat, and combat is very black and white. You either hit the person, or you don't. They are either affected by the blow or not. Taking this, and keeping simplicity in mind it's not much of a surprise that social interactions come down to "roll dice, and binary result". Either they caught you lying or they didn't, for example. Keeping in mind that detecting a lie is generally a reflexive roll (the act of lying itself involves giving the person a roll usually) which is done every time you lie, and even simple lies that people have no way of seeing through can be detected casually in a game.
The way around this is actually really simple, good GMing and good players. Ask the person who is being lied to if they have a reason to believe they are being lied to. Alternatively, tell your players that they need to tell you when they are trying to detect a liar. Abuse of the second one is easily solved with negative reactions from NPCs who are being over-scrutinized, or an abundant detection of little white lies. They'll get the idea eventually.
The problems however still exist with social PVP. Lying can be easily enough done with "do you have reason to believe they are lying to you" but lying is not the worst culprit of what is, in my mind, abusive social skill use against other players. The worst culprits of course being: Seduction and Intimidation.
So picture the scenario, you're playing your character. A hard nosed, rigid, straight laced lawful good Paladin. The rogue in your party is a buxom young lass, but you've observed her ways and honestly she's just not your type. Too low and wrong on the moral scale, not high enough on the strength scale, whatever. However, she wants something from you, she wants to corrupt your Paladin so one evening she sidles up, shares a drink with you, throws some dice and the next thing you know you're waking up after a fade to black, naked and in bed with the rogue.
Alternatively, you're a young warrior, brash and full of yourself. You come into an altercation with another member of the party, you think the sword of mega-asswhooping should go to you. They think otherwise. So you're arguing your case when all of a sudden another member of the party grabs some dice, throws them, and you suddenly back down afraid of the consequences of continuing your argument.
So what just happened? In both cases your character was made to act in a way that was completely alien to them because of the use of a social skill. In the first example our stalwart Paladin (who is probably under an oath of chastity honestly) was made to sleep with someone he neither liked nor was attracted to because he failed to reduce a seduction attempt. In the second, our hot headed warrior who is more likely to respond with violence than backing down when threatened, backed down because he failed to resist an intimidation check. If you don't see the problem in a single die roll dictating to you how your character has to act, then this entry is probably not for you.
Honestly, the only real solution to this in my opinion is that PCs should be 100% completely immune to skills such as seduction, charm, intimidate and their like. A die roll should not be able to tell a PC how their character feels or acts no matter the situation. The player should decide that, that is part of the benefit of being a player. In a world where 5-7 people are running EVERYTHING, they are a person who has one entire person (roughly 20% of the creative/ruling power in the world) completely dedicated to them and what they do.
So, how do you resolve those problems where a player wants to seduce or intimidate another player? You quite simply role play it. Try to act it out, play the characters, get into your character and do it. If need be you can roll the dice for your skill and go "For the record, since I can't convey it, I'm being this seductive/intimidating". Have the GM witness the roll (and the resistance) and decide things. Instead of "you get scared and back down" how about "You get a real feeling that he is going to follow through on his threat, and that he can do exactly that". For seduction? "parts of your body are reacting as they naturally should to this...maybe you had her all wrong?"
The difference though is that we're not telling the player how he reacts, just things he could get from the roll. The player then decides how his character would react. After all, who knows better than him how his character would react to this stimulus? He made the character, he plays him, that is his only job in the game is controlling the actions of that character. So let him do his job, especially with things that can violate core beliefs or views his character has. After all, if a character has sworn off all forms of sex, and has stuck to this, and role played it, no amount of rolling is likely to change his mind. At least not without weeks to months of work. The same with the character who responds to provocation and threats with violence. Why is this time special? What makes them back down when threatened this time, but every other time they attack?
A Small Aside
I figure I should make it abundantly clear that I don't think seduction's sole purpose, or even primary purpose, is getting people into bed with you. This is something that comes up a lot, and it is the view a lot of things use it for, but seduction is nothing more than trying to get what you want via convincing the other person that you have what they want, or that only you can give them what they want.
The same is true of lust. While lust is used for pleasures of the flesh, you can lust for anything. A very common use of it is a Lust for Power, or a Lust for Wealth. These are all things to keep in mind if you are using either one in your game system. Yes the tantalizing seductors and seductresses are bringing up a person's lust, but that doesn't mean that it is lust for them, it is just something the person desires and trying to control that desire to get what you want out of it.
Essentially, unless you have hit a person with a domination spell of some sort, nothing should ever really be dictating how a player acts aside from the player themselves.