You just reaffirmed everything I just said, so I don't see any point in responding to most of it, but I can't get over this part:
... there's no room for "We have a more important mission to accomplish, we can't stop to help." DS9 could tell that type of scenario because there was more at stake than their lives and they had actual missions to perform.
If the Defiant had uncloaked there they would have likely been killed. You say the only reason this worked in DS9 was because they had a "more important" mission, and therefore had a valid reason for backing out.
Meaning that, if they hadn't had that more important mission to get to, the suicidal rescue attempt would
have been the right thing to do.
Do you seriously believe that?