Infinite Jest is so ripe for discussion and analysis but, to my dismay, I personally know 0 people who have read it. Even in online circles none of my online 'acquaintances' have read it, that I know of. And, what's more disheartening, I can't in good conscience even recommend it to hardly anyone I know, given the large amount of work the novel is. I believe it was well worth it, and will continue to voice my own enthusiasm about it, and look forward to a day where someone, anyone, I know has also read it. Now, on to my theories, thoughts and analysis, mostly for my own benefit of thought-organization since none of this will make much sense to anyone who hasnt read the novel (this will have spoilers).
I'm re-reading some of the beginning chapters of Infinite Jest and it's pretty remarkable. A lot of the stuff at the beginning is introduced w/o much context, so the first time through it doesn't necessarily stick with you. And a lot of the details are details about places, characters and events you know nothing about at that point. And by the time you reach the end of the monstrous tome the events and conversations from the beginning are so far removed, they are not even within recall. The opening chapter with Hal is a bit of an exception, and mostly stays in your mind throughout the rest of the book (though, w/o returning to it regularly some details, such as Hal + Gately digging up Himself's head, will likely not be within immediate recall).
But, for example, the 3rd chapter with Hal going to a professional conversationalist (who turns out to be his father, JOI, Himself in a disguise), hints at a bunch of things that only make sense in the light of the rest of the novel. Hal is conversing fully with JOI, apparently, yet JOI insists that Hal is silent. And this is when Hal is only 10 years old. Hal calls this an illusion of JOIs, and we have a pretty good picture by the end of the novel that JOI committed suicide because of his inability to get Hal to 'speak'. It isn't clear whether JOI is so mad that he truly, literally believes that Hal can not or does not speak, or whether he hears him speaking but feels that the things that Hal says are so empty, withdrawn and solipsistic that Hal is effectively, figuratively 'silent' from Himself's perspective. Or it's possible that Hal believes that he is speaking in Himself's presence when he really isn't. We see that Hal experiences periods of detachment from himself [not 'Himself', capital H], where his inner monologue doesn't match his outer one. There's an example of this happening 'before' the events of chapter 1 (and before whatever happens after the end of the novel, whether he drops DMZ or whatever). Specifically his fits of hysterics near the end of the novel, where he has no clue that he is laughing. So while his 'subanimalistic' behavior in chapter 1 is very likely tied to later DMZ use, his inner/outer monologue discrepancy can not be attributed to that.
Also in this chapter Himself references Avril cavorting with 30 Arab medical attaches, and asking Hal about Quebec separatism. In the very next chapter the Arab medical attache receives the sazmidat on April 1 (Avril I). Joelle says near the end of the book that Himself didn't want the sazmidat released but rather wanted it buried with himself. What connections does Avril have with the Quebecois separatist terrorist groups? Did she steal and help disseminate the sazmidat against Himself's wishes? It appears that might be the case. And now, at the end of the novel, Himself's wraith is attempting to remedy the situation, turning to the man that killed DuPlessis, and beat up some Quebecois separatists (perhaps not realizing Gately did these seemingly politically motivated things accidentally/incidentally).
Still another revelation in this chapter is that Himself claims that he has some kind of film cartridge device implanted inside his own cerebrum, emphasizing the literal, physical structure of whatever it is. It is likely that he is haunting Gately and Hal to get them to retrieve this, because it's only through this device that they can possibly craft something to counteract the sazmidat that Avril helped to disseminate. Himself was simply trying to reach Hal with the sazmidat; he had no interest in releasing it ever.
I'm eager to see if there's a point where Himself answers a phone in the book (I don't recall if there is one). It is said in a section here early on that sons answer the phone in the same way their father did whether they knew their father or not. Hal proceeds to answer the phone "mmmyellow", as does Pemulis later in the book. We know Avril isn't a pillar of fidelity, so my temporary theory is that Hal might not be Himself's son, by blood. Rather the result of an affair of Avril's, perhaps with Pemulis' father. This theory could easily be derailed with a little more research, or confirmed if there's an instance in the book where Himself answers a phone and doesn't say "mmmyellow". And actually, just as I am typing this, I recall the physical description of Hal that occurs a couple times in the book. Darker, olive skin, very dark black hair. And now recall that Himself told Hal that his mother 'cavorted' with over 30 Arab medical attaches. Further, in the prior chapter with Himself, it's mentioned that Hal (again, even at 10) is a fan of Byzantine erotica, and in the next chapter, at the Arab med. attache's house, is a stand of Byzantine erotica. Even further, in chapter 4, with the Arab medical attache', note his conscious effor to be 'unlibidinous', and only look at a catalog of women's clothing where the women are clothed, head to toe. Now recall Hal's own seeming lack of a libido (like father like son), when later in the book he says that he's a virgin and pretty much plans to stay that way. While his brother Orin has a raging libido (perhaps not just a personal difference, but a genetic one). Evidence mounts that Hal is not a true, full-blood Incandenza. So I'm further convinced Hal is the product of an affair of Avril, but am pretty much scrapping the notion about Pemulis' father, going instead with the idea that Hal is 50% Arab.
With the last 2 paragraphs in mind recall that Infinite Jest the film, the sazmidat, features a pregnant mother who is also Death. And Himself made this film to reach Hal, on the subject of mothers. i.e. Hal's mother, and the truth about her.
Also in an early chapter Hal converses w/ Mario about Himself's death, and Avril not seeming sad after he died. Mario keeps saying "hey Hal?" while Hal is talking. This could be another case of Hal believing he's speaking out loud when he isn't, because Mario keeps repeating 'Hey Hal?' after he had asked a series of questions, while Hal seems to be addressing those questions. So either Mario, being in some senses simple/slow, is just repeating himself trying to get Hal's attention, but it seems more likely now that Hal just isn't speaking, but believes he is. The first time reading through it seems maybe that Mario is just naive re: the Moms, but in a second read through it seems possible that she just really wasn't sad. That in fact she likely contributed in some way to Himself's death and had nefarious intentions re: his work.
Recall also Avril's affair with John Wayne, both Canadian. Recall John Wayne, wearing a mask, ALSO present at the site of Hal and Gately digging up Himself's head. Perhaps wearing the smiley-faced mask of the AFR. John Wayne is the best young tennis player alive (or close to it), so it's concievable he's so athletic that he is able to dodge trains so well that he is the lead, young member of the organization that feeds members to the AFR. And is embedded at ETA as a spy, or secret operative.