1. Correct. Only the AP rockets use the Small Explosion Template, unless the weapon has any special rules that dictate otherwise.
2. Also correct. It takes only one Action to fire the RL, so a model can fire for every Action if they wish.
3. All the non template RL's are Hit or Miss, so a missed roll with a non-AP rocket will not deviate. Note that the SSW-6500 Stinger RL, on the Scorpion, is an Indirect Fire RL, so it will hit regardless of the roll passes or not, just subtracting the amount the roll failed by from the damage.
Yes, the Scorpion does indeed, rule.
