Does it make the game feel complete?

Yes, especially Insomnia feels much more challenging and harder. And Story bits are always great. It makes me proud of my Chocobros and scared of some sidequests. Also more insight to what people were doing while you were gone, only Problem, i want some teleporters, always running through is kinda annoying in Insomnia some times to me. XD Because backtraking for Sidequests

And now they are hitting me in the feels though. I love the new cutscenes and the Kerberos fight was good.

Does it include all of the DLC outfits?

I think so? Sorry I have the game from beginning + seasons pass and downloaded Royal pack extra. But I guess you get all Episode outfits, can download the free ones but about the Festival outfits I don't know.

Spoiler if you haven't Played Royal pack I love the fact that they add my Comrades character

I found the best thing of this DLC , the last fights before the endboss are so fun, because each character gets his moment to shine.

gordon motherfucking freeman costume