Solution -- don't be a wuss, and come play Sins in online multiplayer (aka the real Sins game) against live human opponents. Just click the Ironclad Online button, register an account, think of a player name, and you'll be good to go.
You'll find that real opponents are much more challenging than AI. Also, contrary to popular belief, most online multiplayer Sins games don't last more than 2 hours.
That's not really a helpful reply to the issue of the AI ignoring key benefits of gameplay. I don't want a short game of rush tactics and lack of total galactic conquest. The AI is ignoring key strategies of the game that could greatly improve its challenge rating.
Find me players who are going to play multiple-galaxy universes for a 6 hour long game over the course of 1.5 weeks and can meet my schedule to resume from saves. You're not going to find them and neither am I. So that leaves me playing with friends and the hardest AIs. I've seen pretty impressive AIs that have taken me long periods of time to outfox, but the Sins AI is lacking.
Can I have a 40 minute game online in a tiny galaxy with players who spam siege frigates? Sure. Do I want to? Hell no. Where's the strategic breadth and scope in a epic 4X RTS like Sins playing like that?
I do agree with you that I would find more challenging adaptable opponents online...and I do play several other games against human opponents. But Sins, due to its time requirements in the manner I would enjoy it, isn't going to be one of them.
For a game lacking a campaign, (and I'm fine with this, I wouldn't play it anyway), it seems like the AI should be far superiour to how it currently plays.