No, I'm with you on Cory thinking the Inquisitor was unknowingly aspiring to godhood. That's why I thought Trespasser would present the Inquisitor the options to A)Become a "god" or B)Die fighting a big baddie/sacrifice themselves for their LI or Solas or something. Both options would have taken the character out of play and opened the field for a new pc. I was disappointed they let my pc live, romantically frustrated, with the pervading assumption that she will never be a playable character again. That just won't do.
Anyway, I don't think it was a writing slip up. It makes perfect sense. Cory also says in the final battle:
"We shall prove here, once and for all, which of us it worthy of godhood." So...there's that. The nature of godhood was actually a major theme in Inquisition. The Evanuris were perceived as "gods" because they were powerful, but does that mean anyone (say even the Inquisitor) who is powerful should/can be perceived and venerated as a "god"? Are all the "gods" of Thedas just powerful mages, spirits, or dragons...things that are mundane parts of the natural world just like druffalo and elfroot? Inquisition was full of major "Questioning Beliefs" moments.
If the Inquisitor/ex-Inquisitor comes back for another round perhaps our characters will be able to aspire to "godhood" if they are arrogant enough...I just hope it isn't handled like the Mass Effect 3 Control (aka blue) ending.
Wow, I completely forgot about that line!
There really is a ton of stuff kind dealing with "God" and the "What is a God" in Inquisition and the Inquisitor's relation to what it means to be in place of power. I mean you can totally play up the Inquisitor as a person who doesn't seek power, but accepts it because they feel it is their responsibility to carry that burden (its optional, but the introduction to "Judgements" really reflects this type of character"), an Inquisitor who is only involved because they have to be, or an Inquisitor who revels in they're power as the Inquisitor (or even the Herald itself).
As much as I was joking about a plot line based around this concept, one of Corypheus's big claims is "I have seen the throne of the Gods and it was Empty" and now I'm really starting to think that if we do go to "The Black City" (Or Arlathan if that is indeed what it is) the Inquisitor would make a really compelling option to sit on the Golden Throne (regardless if it actually gives Divinity or not). Though I suppose Solas is of course another potential option (once he gets over the whole "I'm not a God, I just constantly do things that change the very foundations of Thedas ... but still not a God).
The only thing I do truly believe about "The Black City" (at this point) is that being Physically in the Fade is a requirement to get there and that if we go into the Fade again (or if the Fade returning as a part of Thedas) if you left Hawke in the Fade, we haven't seen the last of them ... though I can't attest to their psychological or physical well being. Flemeth's advice for Hawke in DA2, I still believe it holds water (in fact I set up my entire world state betting on this fact).
"We stand upon the precipice of change. The world fears the inevitable plummet into the abyss. Watch for that moment... and when it comes, do not hesitate to leap. It is only when you fall that you learn whether you can fly." The quest in which you have to decide between Hawke and the Warden is after all called "Here Lies the Abyss".
Outside of this though I hope (at least a little) using some of the evidence (or my perceptions of the evidence) that has actually been provided in game, that there are plenty of story lines that could still effectively be built around the Inquisitor returning as a PC in DA4 and I've attempted to do so by staying true to the stories and characters themselves. I don't know if I succeeded, but I did try to avoid saying I want/don't want this in DA4 because I simply wan't/don't want it, as much as possible. My opinions probably won't change too many minds, but that wasn't my goal. My point was to break the common idea that "there is simply not enough content there for another story to be told about the Inquisitor", nothing more.