Let's recap then and I'll add another clue for good measure:
1) A detail that equally helps sworn enemies but no one else.
2) Someone gets a taste of their own medicine.
3) Extreme arrogance is sometimes punished
4) Second-hand stuff often hides some surprises, some really bad!!!
5) Watch out!!!
6) These Cardassians, always a trick up their sleeve!!
7) You have to admire someone's art of understatement.
8) Things escalate throughout the episode to a climax of dangerousness.
9) Some things from that episode will be used later in a rather improbable manner...
10) There will be a follow-up episode after this one.
Plus one clue:
11) Many lives are at stake!