It's impossible to exterminate alts, without altering the character creation system or highering the level cap. Regardless what you do, it will end in jack of all trades characters, as this is exactly the reason why alts exist.
What's wrong with altering character creation? Of course we gotta toggle the numbers if alts are wished to be exterminated. Players just won't stop what's strongly profitable.
- Reduce the potential which one char can master at one thing, no more 200+ sg snipers. Forces players to spend their skillpoints on something else and won't let them become too accurate.
- pvp system must have features that reward skill, more factors that can be exploited for player's favour.
- Set hp upper and lower limit
- Set ap upper and lower limit *these will prevent players from making intentionally too weak characters and turning this weakness into overpowering strength at some other area.
- The best equipment and temporary perks can only be achieved by npc faction interaction which demands skills in fighting and profesions.
- npc rep could be achieved by killing enemy players, but not so that you grind the same dude over and over again. You must kill various players with as much high status as possible.
- Currently crafting related skills provide nice perk unlocks suitable for fighting or just bonuses to fighting skills, like draconis said.
- Force players to choose fighting and luxury perks. You cannot pick only either type.