My only complaint is that Alphabet probably wasn't a concious choice by cubsfan, but rather what the "advisor" auto-assigned when he received Warrior Code which he was researching before. A switch to The Wheel would be a lot more useful.
I agree that there's likely to be another passage in the south, and finding it should have high priority.
On my own side, I'm finally ready to roll again, and exploring unknown lands:
Lots of interesting rivers, and grassland composed solely of BGs. Quite incredible, but a bit too far to be harnessed usefully. Good thing my own lands are also full of 'em BGs.
I took your image from above and made an overlay of my own zoomed-out world:
As you can see (if you look closely), I have my first settler out. He's going to settle on the hill 2NW of Abstraction, to share the tiles I will improve there. The GA cut me some slack with respect to what tiles to improve, so my worker can walk three turns to improve the northern BGs and maybe irrigate a FP instead of mining the (non-river) BGs in the south.