Your first post on /r/INTP is an attempt to discredit a wide-spread conspiracy theory using only anecdotal evidence and a site which partially backs up the claims you're trying to refute and also lists a site as a source of evidence that can be altered by literally anyone (I'm talking about archive.org). You'll understand if I have to call bullshit. Do you even know what this subreddit is about or did you just go searching for conspiracy theories to refute?

Regardless, I went through the evidence you provided, first and foremost. That site led me to an archive of what we assume is an accurate and up-to-date (for our interests) Master Death File from ssdmf.info. The reason for providing this alternative resource, as listed by the site you provided, is to fill in the gaps of other websites which claim important figures like Dawn Hochsprung and the supposed victims of the attack did not have a death certificate released despite their deaths in the Sandy Hook shooting. So I cracked it open.

First thing I saw? A bunch of names without any dates, cause of death, anything. Already looking promising. Well, I can't use that to dismiss anything just yet. Let's look up a few victims' names, looks like it's last name-first name, so I'll construct my searches that way (will still refer to them normally). Emilie Parker. Nothing. There's an Emily Parker, so maybe that's the child-victim. Next name. Lauren Rousseau. Laura Rousseau and Laure Rousseau come up, but not Lauren exactly. Next name. Jesse Lewis. What's this? 3 results all with the same name. This is really getting somewhere. Noah Pozner. Document 1, nothing. Document 2, nothing. Document 3, nothing. Here's a kid that died and isn't listed whatsoever (no permutations, no Noah Posner, Posnar, Poznar, Noa, etc.). Whatever, let's look at some figureheads. The shooter, Adam Lanza, yep, that name's there. Behavioral therapist Rachel D'Avino. All documents, nothing. Great. Okay, still a few gaps, let's look at what we really came here for, the principal which was missing a certificate on other websites, Dawn Hochsprung. All documents, nothing. Why the fuck did I download this archive again?

This says nothing for the other odd bits of evidence against the official narrative. Why did the SSDI site we're referencing list Adam Lanza as dying a full day before the shootings occured? Why was the school instantly demolished before looking for more hard evidence? There were security cameras, where's the footage? This was a real event, right? What the fuck is this? And are these ghosts?

I'm not buying it.