TBH, I don't mind them cutting a few bits out for DLC, providing that they expand on it, which is what the Omega DLC sounds like.
The Citadel DLC - I'm still not sure on this. The most obvious plot would be that you play someone like Bailey during the Cerberus/Reaper invasion at the end of the game. However, with one small exception aside (Joker in ME2), you've ALWAYS played as Shepard.
I just hope that all of the remaining DLC isn't just mid-game content. Citadel DLC would fill an obvious POV gap from the main game, plus might impact and/or overflow with the ending(s).
That would be interesting and as you say, not unprecedented. Honestly though, it would have been nice to just see a few cutscenes showing the fall of the Citadel. I don't need to play as Bailey fighting off husks to get that. Besides, it'd be a bit of an awkward fit in terms of pacing. Even in ME1 we got to see things that Shepard didn't; Saren & Benezia post Eden Prime, Anderson laying out Udina and Sovereign's attack on the Citadel spring to mind.
In fairness though, just like with the cut Shadow Broker mission in ME2, this was originally going to be a much smaller affair than the DLC, which let's be honest is for the best. I mean would anyone have rather had just a single loyalty style mission for Liara in ME2 instead of 'Lair of the Shadow Broker'? Me either.
That depends. I'd rather have a big post-finale DLC, but a smaller in-product mission if the DLC is going to be a flashback.
Post-finale? No thanks. The endings are what they are and I think they're about done adding to them in any substantial way. Personally I'm all for more mid-game content. Anything to add more scope to a galaxy wide war that we mostly only got to hear about.
This is actually what really disappointed me about Allers. Even before she'd been announced I had thought having an embedded reporter (either Wong or al-Jilani depending how how you treated them in the past) on the Normandy would be a great way to see what else was going on out there. The idea being that there'd be periodic newscasts that would vary depending on your actions, in the game and from imported plot flags. What a shame they made up a new character, cast a non-actor to play her and made her a totally useless waste of pixels.
P.S. Words fail me.