So, I did a fair bit of thinking about this in the recent Catching Up: City Elves thread, but the focus there was more on the hyperbolic bits of the documentation, and the bits that it doesn't cover so well. I'm going to take different angles here.
To recap some of the parts of the earlier discussion that are relevant, the free city elven population is meant to be similar in numbers to the free human population. In other words, a lot of the city is running on elven labour, and while elves are certainly disproportionately well represented among the criminal classes, most elf clans are providing enough benefit to the city to be worth the trouble of having them around. There are some really interesting roleplay tensions to explore here between elven sociopathy to those outside their tribe and elven pride on the one hand, and the necessities of survival as a disliked underclass on the other.
I personally think that while having a place for openly criminal elves would be pretty neat, there's a lot more RP meat in having a Southside clan which has a niche which is not openly criminal and which has to carefully manage its relationships to the powerful. I think this would also go a long way to adjust PC attitudes toward elves to make more sense: your human PC likely grew up on the same street as elves, played with them as a child, buys goods and necessities from them on occasion, drinks in bars which have elves present. They are, it goes without saying, untrustworthy and inferior to humans in every way that counts - but seriously pissing off an elf likely means pissing off a whole elven clan, and that isn't something you do lightly, especially if you lack connections.
What could a city elven clan offer PCs? Quite a lot, I think.
- An elven clan is family. Your clanmates can be trusted to look out for you as long as you are acting in the best interests of the clan. This goes beyond mere employment.
- An elven clan is not a rigid hierarchy with bossy leaders and tight schedules. You fulfill requests out of respect for your elders, rather than taking orders.
- Your PC has clear motivations from the word go: protect and strengthen the clan.
- Newbie support. Making newbies who do want to play elves as their first ever characters read the docs and join a clan would, I think, vastly improve their first experience of the game. For this to be an option though, we first need clans.
- Room for interesting gemmer roles. While clan magicker numbers would have to be monitored harshly to prevent X-Men syndrome (perhaps only one gemmed in the clan at a time or something), elves are much more likely to accept a magicker sibling as one of theirs.
I think the circle of trusted tribemates would go a long way to counterbalance the human advantages of employment and mount-based mobility. Sure, Amos and Malik the independent hunters can team up, but Amos doesn't know for sure that Malik won't steal his mount, slit his waterskin and leave him to die in the desert.
What are the difficulties?
Well, any such clan would depend heavily on trade, and it can't just hire in crafter PCs when it has a lack. Some care would need to be taken over crafting the makeup of the clan so it has reasons for interaction with other PCs and pressures to attend to. The basic description of the elven mindset in the docs is hazardous to continued PC survival never mind clan survival - it would be imperative that players, including newbies, didn't favour kleptomania over keeping the powerful placated. It would pull a bunch of players away from existing clans and spread us all a little thinner. Lastly, and perhaps hardest to bridge, is how such a clan could interact politically. Vastly weaker than a great House, noble or merchant, it would have little competition on its own level to deal with - it would essentially be playing on the same scale as the Byn, which is little more than a tool to be used by the powerful. There is a real danger that any such clan would cross the bored sights of a Merchant House player determined to take offence and be exterminated.
If some way could be found round the difficulties, I think there'd be room for something pretty awesome. The adjustment in reactions it would provoke would also I think make even unclanned elves a little more interesting to play.