If 1982 wasn't the most important year for the X-Men franchise up to that point, it was certainly the most important year in which UXM wasn't either starting up or being cancelled.
The reasons for this actually have very little to do with UXM itself (though we'll come to the parent title), but with two graphic novels, and a limited series, each of which can be considered patient zero for trends that continue to this day.
Exhibit A is the Wolverine limited series from Claremont and Frank Miller. I've read almost no comics from the early '80s, and I'm not sure I've read any which didn't star mutants, so I can't pinpoint the exact moment that mainstream comics in general started to take on darker hues (though this was the year that V For Vendetta, for example, began appearing in print), but this four-issue limited series was certainly the first time the X-books delved into actual murk, rather than just melodrama (which is not to say - Gods, it is not to say - that the miniseries in question lacked for melodrama).
This desire for grittiness and what a PCP-addled Klingon might mistake for realism would eventually consume pretty much the entirety of '90s Marvel output, of course, as well as creating some kind of hideous temporal anomaly in which people could spend six years calling Rob Liefeld a visionary whilst keeping a straight face, but I'm not inclined to blame Claremont and Miller for that. Well, not Claremont, and not Miller because of this: if anything he did was responsible, it was Batman: Year One.
As well as sketching out the direction the X-Books (along with all the other books) would take over the next fifteen to twenty years - by the X-Tinction Agenda even Claremont was writing stories in which our heroes march remorselessly through the blood of their enemies - this initial foray into the limited series format proved a harbinger for an almost unstoppable flood. During my first hesitant footsteps into the X-Universe (starting with UXM #323, for the record), I rapidly lost count of the number of tiny editorial boxes advising me to pick up some limited series or another. Why, to a cynical mind (and even at fifteen, I was plenty cynical), it might appear that each of these ubiquitous series were just vehicles for a single development the ongoing titles could reference as "relevant", whilst being entirely creatively barren in every other respect (like if in the last episode of Desperate Housewives they'd literally dragged Obama onto the set and shot him).
Sticking with the subject of the opening of floodgates, let's talk about MGN #4, in which the New Mutants are introduced. The setting of precedent here is quite obvious; the formation of a new team for completists to buy alongside UXM, and for newcomers to read without the crushing weight of canon threatening to, er, crush them. The story itself sticks to an established idea - one man visits a bunch of prospective team members and persuades them to sign on - and there's still a slightly disagreeable whiff of short-cutting via stereotype - the Brazilian is hot-headed, the Asian girl is polite, the Native American will not stop whining about her culture - but there's no denying the impact this book had, either in direct terms (New Mutants is currently on it's third incarnation) or indirect (even I'm not mad enough to count how many X-teams have existed in the last thirty years). Indeed, whilst I argued the contrary a few months ago, it's certainly plausible to claim that Renewal marked the beginning of the mutant franchise, Dazzler being closer to a Marvel team up book than an X-title.
Lastly in our list of game-changers, we have God Loves, Man Kills, which I posted about the day before yesterday. This is by no means an unalloyed success (having a white man write about a Jewish girl schooling a black woman on bigotry is particularly problematic), but for all it's problems, I maintain that it's an important and welcome step up in terms of the handling of the mutant metaphor, and even if I'm wrong about that, it certainly shaped the way the X-books presented the mutant vs human angle, right up to this day,
So, that handles the paradigm shifts. What else was going on in 1982? Well, Dazzler seemed to have some trouble deciding exactly what it wanted to be, starting the year as an intergalactic/interdimensional romp through the universe, before switching gear and becoming mired in increasingly implausible family soap-opera. Yes, I know, I'm never happy. In fact, I specifically said I wanted more of Dazzler's personal life at around the time she was weighing up whether or not to punch Galactus in the crotch. Actually, I think it's definitely the case that Dazzler ended 1982 in a better place than where it started, but the nice balance -and lack of outrageous self-absorption - that made the first few issues so interesting still hasn't quite been recaptured.
And as for the scamps who caused all this mess? UXM bookended the year with extra-terrestrial jaunts, first with Lilandra against the Brood, and then with, er, Lilandra against the Brood. And to think Jon Seavey claimed the Silver Age was more inventive...
Just kidding, obviously. Actually, Seavey's got a damn good point there (his musings on Claremont's consistent time-keeping that led to the creation of this very blog, on the other hand, are almost charming in their naivete). Between these trips to the stars, the X-Men break into the Pentagon and fight Rogue and Mystique, briefly lose Storm to Dracula and Illyana to Limbo, and delve into Magneto's origin story. That should be enough to keep everyone happy. There's really not a lot to say here other than, like 1981, this is classic Claremont.
In summary, then, this was the year that started the boulders rolling; boulders that would eventually pick up so much detritus that their weight would almost crush the entire franchise to nothing. Of course, the Hindenberg eventually crashed and burnt in a horrifying inferno. Doesn't mean that the first airship wasn't a hell of a lot of fun to ride in.