There can never be too many rewatch threads! And you've been busy today!
Emissary was without a doubt the best opener of any Trek series. It grabs you right away with the Wolf 359 sequence, which was an epic one for it's time. Seeing Locutus and the Borg's victims from another perspective really puts an interesting twist to the norm of things. You even see the tension in the air as Picard and Sisko meet years later.
Emisarry really did what it was supposed to do. Introduced us to the characters, Bajor's backstory, the bad guy in Gul Dukat however minor his role was, and the unforgetable character of Kai Opaka. I wish she was around more, because she was really convincing and powerful in her role as the religous zealot.
Past Prologue... the problem here is they tried to do too much. Backstory on the Bajorian terrorists. Bajor not being unified, Cardassians hunting down rogue terrorists, the Duras Sisters somewhere in there, and Garak all in a jumble. Garak is epic. No more needs saying there. The Duras sisters were nice to see(Klingon Kleavage or not) but really didn't add anything to the story beyond a blatant attempt to bring some TNG fans over. The Kohn-ma were very compelling and interesting. So naturally we never see or hear from them again. It's a good episode, but nothing special. Clearly the DS9 table is still being set in this one.
A Man Alone... clearly this was an attempt to introduce Odo's character and flesh him out a bit, but the story really did fall flat as a lot of DS9 season 1 did. Thankfully they did bet better as you said. Jake and Nog's antics on the station when they were kids, I actually enjoyed... young people being young instead of annoying twerps like Wesley.
Babel was just silly. Babel, babble? Nicely named I'll admit. Other than that it was your generic save the day before everyone dies episode. Not great, but not terribly inspiring.