I'm wondering is the WS/BS bonus from a custom grip stack for talents like Crushing Blow when calculating the WS Bonus?

Or are boni only calculated of 'raw' characteristic stats?

No, it doesn't add to the Characteristic Bonus.

As mentioned above.

The reason for this is that Weapon Mods/Quality (i.e. the +5/+10 from Good and Best) add a bonus to tests using said weapon, they do not provide a bonus to the wielder's characteristics. Unless of course its mentioned in the weapon itself, such as in a Relic that increases your stats through arcane or ancient means.

Thank you both for the quick answers.

As mentioned above.
The reason for this is that Weapon Mods/Quality (i.e. the +5/+10 from Good and Best) add a bonus to tests using said weapon, they do not provide a bonus to the wielder's characteristics. Unless of course its mentioned in the weapon itself, such as in a Relic that increases your stats through arcane or ancient means.

Oh cute, where can those relics be found?

I guess those are unique items which can't be simply procured.

There aren't any stats for them, at least not that I know of, though throughout the Enemies books there exist mentions of such items. In the end its up to the GM what Relics they want to create/use in their games.

Ah, okay. Maybe I can make it a personal goal for my character to search for such relics. To restore them in proper order and have them worshipped in a cathedral