The powers there pose no threat. To go to war with them would be an expenditure of military resources, not major since you probably won't take many, if any, losses, but still an expenditure. Finally, once you obliterate the powers of the AQ, the Dominion, the Borg, and every other race, you're left with a second galaxy that needs occupying, garrisons, and the like, and one that has an infrastructure millennia behind the Empire's, requiring material and resources to upgrade to the standards of the GE.
Now, I know Mike's reason, namely, an enemy to distract the common citizen from the Empire's internal problems, a unifying force. But actually conquering them makes this only a temporary bonus: once the enemy is vanquished and occupied, the same old problem pops up.
So, my idea is, why not get the best of both worlds? Move through the wormhole, whatever it is that links the SW Galaxy to the ST Galaxy, encounter the UFP, and then back home use propaganda to make the UFP into a bigger threat than it really poses (Much bigger threat, actually

Maybe, eventually, the Empire would go ahead and conquer the UFP, but for the most part it's smarter to leave them "intact" and use them as a bogeyman for the citizens of the Empire to rally against.
So, what do you think? Good point and idea? Bad? Should I go lay down and lay off the M&Ms for a while?
