Working from what Deusovi has found, we expect that we need six of something. The following letters appear exactly six times in the grid: A I V W. I would guess that we want door 1 on whichever path, since A is the only one of those that fit within the 5 possible doors. (However, as Zipzit pointed out in the comments, the grid is 18x18, and 18 is six threes.)

As for he "gems of four," since we have so little to work with they must be within the grid itself. I tried breaking the grid into quarters, but found nothing of note.

Next, I attempted to remove all letters, leaving only 1s; I believe this is how Deusovi found the first message, but maybe someone else can find something new in it. (I'm afraid I'm not sure why it's skipping lines.)

11 1 111 11 11 11 1111 111 1 1 11 1 1 1 1 111 1 1 11 1 111 1 1 111 11 111 1 1 111 1 1 111 1 1 11 1 11 111 1 1111 111 11 1 111 1 11 1 1 11 1 11 1 11 111111 11 1 11 111 1 1 1 1 1 1111 1 1 1 1 11 1 1 1 111 11 1 1 11 1 1 11 1 111 111 1 1 1111 1 1 1 111

On the other hand, if we convert the grid to a single string by reading left-to-right, starting at the top, we find the following letters immediately following groups of exactly four 1s: Q C T A I.

If we look at only orthogonal groupings, there are two groups of exactly six 1s. The letters orthogonally adjacent to them are VKRNIP and DKJGEPYNEUDI.

I'm largely just grasping at straws, but maybe there's something in this madness that someone can use.