Surely starting off in 2nd would require more torque than 1st as you are using a stiffer gear (speaking of cars that is)? I would start off in 1st but using very little if any acceleration, that way I start the car rolling with the maximum bite into the slippy surface but with the minimum force.
If you try to pull off in 2nd you may find you need more acceleration and therefore more torque and more likelihood of wheel spin.
Its the same when you are cycling; if you start off half way up the cassette you will spin the rear wheel in snow or wet road so you always start off in 1st; less torque.
Of course if you accelarate in 1st like a looney then wheel spins you shall have.
Descending in low gear makes sense and if you want to warn the driver behind you can touch the brake without engaging brake pads and you will engage the rear lights without braking at all.
But what do I know? I'm just an advanced driver