You have great points as usual, Nasat. Still...it should be worth noting that in Avatar, Ezri suddenly said she was going to leap in the opposite direction of her original plan--instead of setting herself apart, she claimed she needed to try and integrate past hosts into her personality.
Of course, by This Grey Spirit, we saw her error along with Bashir--and to an extent, so did she...but she didn't really do much about it, leading to Unjoined.
I think by Destiny, she more or less returned to "equilibrium", but still....
BTW: Needless to say, I most strongly and vehemently disagree with the denunciation and genral shrug-off of Ezri Dax by Dukhat. Claiming she is "whiny" because she is open and honest about her vulnerabilities is a most unfortunate mischaracterization.
Furthermore, as to the argument that Ezri's presence ruins the effect of "people die in war"...ah, no, just the opposite. Her presence--and the other characters adjusting to it--is the living embodiment of people acknowledging death--and recovering. Remember the emotional support Jake noted that Ezri provided to Sisko, just by her being there. The same goes for Julian Bashir...and, eventually, for Worf. Many were the references to the fact that Jadzia was dead.
After all--what would be the alternative? Having the characters sit back and reflect on "I wish Jadzia were here..." reminiscing, expressing grief at her death--to the point of it getting old? Or having them "get over it", and then not really bring it up--which would have been nonsensical?
Also...as TPTB noted, it allowed them to finally do what, in hindsight, they should have done a long time ago: explore the process of a Trill adjusting to the changes in life initiated by a recent joining.
Therefore...if anything, the transition should have happened earlier. Or at least--as I have said--it shouldn't have ended with Season 7, but 8.