Every school orders the applications differently based on different factors. I would guess stats are a big factor and they prob prioritize IS.
They said 6 weeks is the average but again, it varies by where they place your app in the pile. I’ve heard that some hear within a few weeks and others hear months later. If I recall correctly, they will let you know whether you are A, R, or final pool once they get to yours. So my guess is that they just have not gotten to your app.
I can’t answer the last one for sure, only speculate, but I’m sure they look over your application. Not that it really matters, since the interviews themselves are blinded.