I agree with all of those on your list except the Klingons. Why no Klingons?
Agree with all of these apart from Klingons and no TNG/DS9 elements. I think having the TOS crew face the Borg could be pretty great.
Although a huge part of Trek, I've gotten really tired of the Klingons. With the introduction of Worf there were just far too many Klingon-related episodes, to the point where the concept of Klingon honour was more of a caricature of itself than anything else.
Add to that the NuTrek blinged-out Klingons who just look ridiculous, and its something I wouldn't find hugely appealing for a story. Now if it was something involving the Tholians I might sit up and pay a little more attention, though my hope is for an original baddie.