1. Yep, always dry unless stated otherwise.
2. Torque is just a turning force so hopefully the value given is lower than that which will snap the bolt but enough to stop it undoing itself. It'll be where the bolt just starts to stretch but before it breaks.
3. No, they will be different.
4. See above
5. Hold it on the grip. Torque is force multiplied by distance so if you change the distance you alter the torque.