Which is the point I was making. Normal driving isn't going to blow them up. Even making huge hp and drag racing isn't going to blow them up.

But if you allow the wheels on the front to spin while under power while the rears are locked up you can in fact damage the torsen.

 

I am interested in sliding around on the black though - maybe wet. So is this definitely a bad idea then?

 

If the ground is all wet and you are a competent driver, you shouldn't have to pull the e brake to slide the car around. Its best to have power applied to the drivetrain at all times when in a slide, personally i haven't seen any damage from pulling the E brake though, but i wouldn't go pulling it on dry pavement over and over again to find out.