Currently +1 vs shapechanger items have no effect on the shapechanger subrace. I've played as a shapechanger on other servers where these effects do actually work (for example arrows with 2d12 magic damage vs shapechanger working vs pcs). I think its really important that at least while shapechanged the were person must count as a shapechanger for the purposes of DR.

He had ghostly visage up aswell but even so the +1 is vs race not spell type.

This is because our lycanthropy scripts use set appearance + skin changes, which allows us a lot of flexibility in various ways, as default polymorphing is kind of clunky. However, you're right that items specifically against shapechangers (such as silver daggers) will not be effective. There is no way to fix this with our system, and since we like our system better than most true polymorph lycan scripts it probably won't be changed.

Normal +1 weapons (e.g. from magic weapon cast by a cleric/wizard) work perfectly fine.

Sure adds alot of power to lycantrophies. 10/+1 dr is very nice especialy if you manage to ambush a warrior alone its doubtful he'll be able to cast magic weapon, although he could have an odd weapons charm lying around.

Lycans are bad, but also consider this: There are alot of weapons that give +1 to certain alignment, race and countless amount of charms and spells for magical weapon. It shouldn't be too hard. And I believe, that those who gain the lycanthrope are known and respected players, that also can be trusted not to abuse their power.