SGA canon & Things Already Seen

I asked this question more generally over at writers_lair, but I'll repeat it here, with specifics (and choppy sentence structure because I really ought to be going to bed at this point): in turning Things Already Seen into a novel, how much of later show canon should I use? Obviously, events won't play out the same, but my question's not about plot, or even character development, but more about the allies/available materiel that show up after season 1.

Post-season 1 stuff I'm interested in exploring:
* Anything Ancient/Alteran-related (the ships that are found and then almost immediately lost, the outposts that show up in one episode and then are forgotten, the people that could have been resources but die/are forgotten, Atlantis herself, who is mostly ignored except as home base)

* Wraith-related stuff (Steve, or his equivalent; Todd--I know that episode happens a good bit later, but so much potential there; using the Wraiths' own tracking devices as bait for ambushes, etc.)

* Ronon & Sateda (but I have to figure out a way to get him into the story without being obviously shoe-horned in)

* All the different, crazy/stupid/nasty ways different cultures come up with to try dealing with life in a universe where they're considered cattle.

Post-season 1 stuff I'd rather ignore entirely
* John Sheppard's personal history. Pretty much in its entirety.

* Easy access to Earth. A once-a-year supply flight? Sure. Weekly 2-second info-dumps through the gate? Maybe. Anything more than that and you lose the we're-on-our-own effect that I found so interesting about the first season.

* A lot of individual stuff, like "Sunday", the Lucius episodes, the whale thing, the Asgardian thing, etc.

* The Replicators. (Maybe. I'm on the fence about this one, but it's sort of a case of "I don't know what I'd do with them".)

So basically, how much cherry-picking can I do without it bothering the audience? What baddies/allies/technobabbly things would be noticeable in their absence? Or backstory? I have this horrible feeling that I'm going to have to stick to the "Outcast" version of Sheppard's history and I don't want to.
Hm,I don't quite get the question. The way I see it is: you're writing an AU that takes place in the general background of the canon universe: Pegasus is basically the same, the Ancients, the Wraith exist, Atlantis still exists etc.. So, depending on how your story develops,what you want to write, where you want to end up, details of events and things happening (or not) are bound to change.

On the specific points:

Replicators - well, they played a rather important role because a lot of events are the results of encountering the Replicators and changing their base-code. Depending on which point in the time line you want to change their interaction with the Replicators things will very much change. They never meet the Replicators means that, as early as The Return, events change. The Ancients would keep Atlantis because the Replicators wouldn't even know about Atlantis still existing let alone being able to attack Atlantis because their base code was never changed. If you change the Replicator storyline at a later point, the later depending events will change also. But you know that already, so I don't quite understand what you're really asking. :-)

The same is true for the individual things. Some of these have an influence on later happenings, some not. If they never meet Lucius they'll likely never meet Kolya on Lucius' second "home"-planet and John won't kill Kolya then and there. Ignoring the whales means that they'll either die because they didn't get a warning about the solar flares or you could go with "the solar flares never happened in their time line". And so on ... whatever you decide, it will have an influence on how canon would have played out. Deciding what to skip and what not depends on where you want to go with your story. Do you need certain things to happen? Do you need certain things *not* to happen?

Re: John's personal history (as seen in Outcast) well, we get so little facts from this ep that one can pretty much do what one wants and still make it matching canon. What did Patrick Sheppard do before he became boss of Sheppard Utilities? He could have been a decorated officer who quit for whatever reason you want him to quit and then took over the business from *his* father.

Or Patrick could be John's adoptive dad and John's real father was an entirely different person. Hell, John could be a completely adopted child for whatever reason. Perhaps he was the son of Patrick's sister and *she* was the head of Sheppard Utilities (or her husband, if you need it to be a man). When she and her husband died in an accident, her brother Patrick became head of the company and he adopted her son John, trying to raise him to be the next in the line. Two years later Dave was born etc.

See - you can do anything you want because there's just so few facts. The name Patrick, the fact that he was the head of Sheppard Utilities when he died, the man who goes by the name Dave and is considered to be his brother, the fact that John grew up in different places and didn't want to become boss of a company, the fact he had a fallout with his whole family (though we never learn exactly why). The fact that he was married once to a woman named Nancy though we never learn how long ago that was (we know she saw him four years ago for the last time - doesn't mean they were still married then or freshly divorced) , how long they were married at all, kids (death or alive)? Hi mom isn't even mentioned. We don't know if she's dead or alive, we don't even know if she was there to raise him or if he was raised by Patrick alone - or perhaps not even that but by the hired staff.

If you want to twist John's personal history you can do a lot without outright contradicting canon, if that's important to you. Actually, John's history is the only thing that I would consider problematic changing completely because it made him who he is and if the story starts out with a canon John who goes back in time for a year, then you start from canon John with canon history.

Or you can say that even this starting point is already located in an AU in which John grew up differently. He, you're the author.

I'm sorry if all that isn't the answer you're looking for but honestly, I don't understand what exactly the problem is. :-)

Edited at 2014-09-05 09:52 am (UTC)
Yeah, the main issue I have with Sheppard's family history as given on the show is that prior to "Outcast" airing, I had completely developed one on my own--and it's pretty much entirely incompatible with the one given there. But as Sholio points out below, as long as I make clear what the divergence is and why, the reader probably won't be bothered by it. Especially given the overwhelming number of SGA super-AUs. This is the fandom where someone wrote a story about the main characters as cookies, after all.

I really just needed to be talked out of my tailspin, so thank you for helping with that.

Edited at 2014-09-06 02:08 pm (UTC)
From reading this, it kinda looks like you're basically just going AU at the end of season one -- so why not?

As a reader, I generally want to know what the points of divergence actually are, because otherwise it throws me out of the story in the same way as if the writer screwed up some canon detail (so if, say, I was reading what I thought was a canon-compliant season-three-era fic and then there's a thrown-in reference to Atlantis getting its annual supply flight which is the only contact they have with Earth, I'd go "whaaaaaat"). But really, it looks like what you're doing is mostly taking off in a different direction after season one, so why not just declare it a post-season-one AU and then write whatever you want? You can still bring in stuff that was introduced after season one (like Todd or the Ancients), but readers will know that anything could happen in a different way, and won't be surprised by it.

And really, it's YOUR story, so if you want to declare that everything is the same except they're all Muppets, that's totally your prerogative as the author. XD
Thank you! This is pretty much exactly what I needed to hear. I'd nearly talked myself into it, but needed outside validation.

(I'm very good at talking myself out of doing things, but not so good at managing the opposite.)