Nope everything is unlockable in one playthrough (two emma scenes are in the emma solo ending tho).HOLY SHIT! Ok, the next episode is gonna be insane, that last chilling revelation explains so much!
It was a sudden end. It seems on my essentially perfect playthrough, 4 gallery entries in a row are missing as well as another 2 in a row. On sky, 3 scenes are missing. I presume this should be normal? Unless some scenes and gallery entries are only unlocked through the less favorable options, or through specific routes of pushing the other characters out, perhaps in Skys' case, although I won't confirm that given how long I would have to hold the control key for to get through everything again.
You can press tab once instead of holding control