1) No, its so ugly it looks like it belongs in the water. It does not have cannons, or a lance cannon, so why make it the skin of the Gallaxy X? What we need is a carrier ship to counter the Klingons' carrier but I would not use the Jupiter for it. Its too ungly.
2) Sure, why not? It already has the same body style as an assault cruiser.
3) Yes, give it 3 shots as long as the damage is 3 times as it is now. For example, 1st shot breaks the shields, 2nd shot does 25% damage to hull, 3rd shot 25% more damge to the hull. If you catch a ship with the shields down it should almost destroy that ship. If it's a hull class less than a cruiser it should be a kill.