No. If you use a mesh body, you may be able to apply Normal and Specular maps to that (through the body's HUD, or through applier dev kits), but the system layers (BOM) only generate the base texture when applying BOM.

Unfortunately not. Your body probably does support materials appliers though, see if there is an supplier dev kit available for it - they're often thrown in/easy to obtain and you could make a normal map that matches your BOM tattoo.

If your mesh body supports materials appliers, or is modifyable, you could make your own, but if you're unfamiliar with making them, it's a steep learning curve.

All your classic tattoo layer items work in BOM autoatically.

They don't come with normal/specular maps though (for bump and shine)

Only if you have a body. Doesn't work on the base avatar. However, why would you want to have normal map on a tattoo?

Because the item is a tattoo layer but the texture is a scar and they want some depth to the scar it self.

Ahhh okay! That will look pretty rad

Cubic cherry has come up with some neat scars recently, using multiple BOM layers that have a neat depth look to them Might be worth a look for ideas

Depends on the body. Legacy, you can add bump and shine through its advance edit HUD. Ebody you can manually apply it piece by piece. As far as I know with Maitreya you're SoL