The idea is terrible as a movie and wonderful as a mini-series.
First, I'd leave dead or "lost" characters out -- no Sisko, Data, Kes, Tasha, Neelix, Jadzia......
Next, not too much redundancy -- they could barely find anything for Crusher to do in the TNG movies so how many Doctors/engineers would they need?
A "impossible mission force," would be best. Best fighters Worf, Tuvok, Kira...best pilots Paris, Nog....best engineers Geordi, O'Brien....a doctor Bashir or Picardo..... best leaders Riker, Kira...... spies Garak, Odo....
A mini-series format could give us some time with people who wouldn't be on the mission -- whereas they would make a movie bloated.
Using the DS9 station as a jumping off point would be a way of giving us a chance for cameos by Leeta, Rom, Keiko, Jake, etc.
Also the mini-series format might entice some of the 'cast directors" to participate even if their acting parts were rather small -- Frakes, Burton, Dawson, MacNeil, etc.
Lastly, as in any "Magnificent Seven" type story -- many/most of the cast should die. That would give a sense of both high stakes and closure.
And it all should have happened in say 2006 or 2007 -- the 40th or 20th anniversary of the franchise (or the spinoffs.) Most of the cast are now way too old pull it off.
And time travel
