Thanks for your replies and for trying to explain this to me. That is really worth a lot. I'm also sorry for dropping out of the discussion for a few days because I had exams to attend to.
To the point:
I absolutely love your ideas for the ion cannon. It's a very good chance to specialize this weapon more (and perhaps give it a more reasonable price in return) and also to make it more interesting and more in line with my expectations of what an ion cannon should do (Star Wars ftw). I totally get that you want make things awesome like this and I wouldn't want to stop you. However, the thing is I'm a huge fan of the whole "range advantage" concept in any game. I just love watching devastating projectiles fly across insane distances so naturally I hope for AI War II will float my boat on this as well - considering classic did such a good job about it when compared to most other games.
That said, I think range advantage is not a weak base per se. This strategy has always played a role throughout the history of war and in almot all strategy games. Even the most close quarter, in-your-face dueling RTS like star craft where units essentially face-hug eachother because there is no zooming at all, they still have long ranged units (siege tanks). However, the problem is certain aspects of it don't really work in AI War which is probably what you see wrong with it. One such aspect of long ranged units is, for example, is being able to capitalize on terrain (putting siege tanks on high ground to increase the enemies travel distance).
Think about your idea for ion cannons and you'll realize that -to an extend - you wanna make them work with whatever kind of terrain AI War offers (solar systems). I think it's a very good idea and hope you'll continue to explore this for the 1.0 release. It's all I can hope for and I'm really looking forward to see how things will turn out on that front.
Definitely looking forward to interplanetary weapons of any sort!