To add an ion cannon in the front part is an excellent idea

-Angel

Maybe the lower "bulb" on the front arm could be used as the ion cannon. It would definitely make these ships more formidable in battle, especially after we saw how vulnerable the SDs were to ion cannons.

Maybe that could be another idea as to how the Executor is destroyed: have it hit with multiple ion cannon blasts as rebel transports ram into it after the ion blasts take out sections of the shields (or the rebel ships with the ion cannons ram into the Executor, as they fire a continuous beam to allow themselves to get through the shields and hit the E). You could still take that shot of it turning downwards, but you would have to add a LOT more damage (along the lines of STAR TREK 3, ST: NEMESIS or the blimp at the end of ROCKETEER) and show the ships ramming into it, either in that shot or a previous one.