That was a pretty long-winded explanation on art to start things off
. Not that that's a bad thing. I consider anime series a form of art - everyone takes away from it what they want. It's just a much more straightforward art form than, say, paintings because animes usually have a clear-cut story to tell (Although every now and then, shows like
Penguindrum like to throw a wrench into this nice and orderly structure).
From what I've heard about the term "meta" and my personal experiences with it, I'd say both of you weren't quite on point there. Well, that sounded kind of arrogant... I'm just going to say I disagree. Meta refers to the meta level, so when the subject in question is an anime series, the meta level would be the anime medium (or a subcategory such as a particular genre of anime).
Now, when an anime character breaks the 4th wall, I don't see that having any meta reference at all. If anything, it'd refer to the meta level of "video" (which usually employs a camera / point of view which the characters aren't supposed to be aware of). Also, I don't think self-reference has anything to do with it.
A perfect example of meta commentary, in my mind, is a line by Konoka from
Negima!? in reply to someone suggesting that another character might have taken a toilet break: "Anime girls don't go to the toilet." That's meta humor because it references (a common convention in) the anime medium.
You hear the term "meta" used a lot in the gaming scene. Different people have different understandings of the word there, as well, but most of them are pretty similar: The "metagame" does not look so much at the actual happenings in the game itself but rather at the way the playerbase sees it and approaches it (which you could call "conventions").
Lastly, I agree with you that instances of meta commentary are not something that's only for hardcore otakus to grasp; my above example should be comprehensible to most anyone who has watched just a handful of anime series (possibly even to non-anime-watchers if they put 1 and 1 together). Of course, there can be obscure meaning in there which requires a lot of anime knowledge to interpret, but that's coincidental.
Also, I think narrowing down the meaning of a parody is much easier than you made it sound
. At least from my point of view, a parody simply makes fun of another work of art (by pointing out its silly aspects or adding such silly aspects to it), usually of the same kind (i.e. anime). I suppose it
could make fun of itself (like short anime specials of, for instance,
Toradora! or
Accel World) or the medium as a whole, but I see that as an exception to the rule.
As I mentioned in a different thread before, studio Shaft's
Negima!? gave me vibes of a parody to the earlier
Magister Negi Magi, simply because of all its goofy (-> silliness) character comedy, which wasn't quite there in the former show. Strictly speaking, I don't think it qualifies, though, because
Negima!? very much tells its own story which can be understood just as well if you haven't watched the first
Negima! (which is sort of how a parody is designed - targeted at an audience which is familiar with the original work).
One last point: I don't quite understand your angle on how deconstruction is strongly tied to words. Yeah, words carry different meanings (more precisely, connotations) for different people, but I honestly don't see how that's relevant to interpreting a deconstruction. For that reason, I don't follow why
Bakemonogatari's wordplay would bring it any closer to being a deconstruction. At least that's not something that would completely subvert my expectations of a harem series...
. I'm still not really sold on 
