How would you improve on BM1?

Example wrote:I really liked the game play of BM1. I don't think the story is really as important as improving the game play. Games like Starcraft prove this point because while Starcraft's story was good, it was it's solid gameplay mechanics that kept people playing for years to come (I mean years, have you seen battle.net lately?!)

In BM1 I liked the core mechanics of it, but I felt it to be too easy. Not challenging enough. I would have liked to see more of a challenge in the system because then it will feel even better when you finish it. I hear a lot of people saying they want more species and such, but I don't think that is really quite neccessary. I think what is neccessary is to think of this as it is. The Star Trek mirror universe. I find it hard to believe that if I attack an outlying Klingon planet I won't have the entire Klingon fleet either counter-attacking or raiding my planets. Likewise, I feel all the major groups are a little too easy to overthrow. With the Cardasians having three or more starbases defending their home world, why is that the Romulans only have one?

The bottom line:
If I could remake BM1...
(1) I would make some kind of requirement before you can buy your own planet. Such as having to earn an insane amount of cash to buy a planet (or at least buy the equipment and move in a population) for each planet.
(2) I would make it harder to either A: Amass a fleet large enough to wipe out an empire, or B: make enemy empires a lot tougher.
(3) I would make enemy raids on your planets far more severe, as I feel an invasion should be an all-or-nothing endeavor. Not wave attacks.
(4) I would make some kind of extremely difficult end-game challenge, like a Borg invasion once you conquer most of the galaxy. (See http://www.kongregate.com/games/ZigZaGame/the-great-war-of-prefectures for an example of how this makes an ordinary game extraordinary)