alt vaulting is fine. honestly i dont see why everyone is so anti-vaulting. least salem doesnt suffer (yet) from the old hearth vaults of haven. where you almost have to rely on the devs to nuke the place..
as well the only thing of value i have ever deemed worthy of raiding is higher purity seeds i dont have. iron is hardly a hard item to aquire. given the fact iv walked by about 7 unclaimed unwalled mines in my travels around darkness zoned areas. so the only hard thing to actually get are purity items. like dowsing rods and seeds, town raiding to me on paper has nothing to do with looting the place. its all about crippling your enemies to the point they either give up and relocate/quit or submit to whatever demands you had which started the fighting to start with.
simply because to be frank. the majority of the raiders in salem already have a town setup to providing X raider alts every X hr/days so they typically have no reason to raid a town for 0% iron ore or bars. when back home they have a house built out of ironbars (minecraft style)..
raiding a hermit by a hermit i can see value in 0% iron if you lack iron your self. but raiding a town meh the only reason to do so is to cripple them or impose your will upon them.
plus demanding an end of alt vaulting would actually be a game rule which to be frank would go against the sandbox system sea tribe typical runs with.