Over the course of 2 months of obsessive, unhealthy gameplay, I found and made note of all these things.

Guardian Temple(280, 760)

Village(644, 692) Village(-1468, 4) Village(-508, -652) Village(788, -860) Village(-1788, 1284)

Stronghold(608, 1984) Stronghold(-1552, -256) Stronghold(1168, -1088)

Jungle Temple(1384, -1864) Jungle Temple(1112, -1464) Jungle Temple(888, -1880)

Desert Temple(184, -4056) Desert Temple(792, -4392) Desert Temple(776, -4856)

Igloo(-1992, -1464) Igloo(-1992, -1704)

Nether Coordinates

Nether Fortress(-325, 187) Nether Fortress(187, 347)

Back to Overworld coordinates

Mushroom Island(-3739, 1503) Stronghold+Mushroom Island(496, 4912)

Witch Hut(3208, 1064) Witch Hut(3624, 1096)

Biome Coordinates

A smattering of Extreme Hills biomes all around spawn

Mesa+ Biomes all around (6064, 726)

Ice Plains Spikes(-1657, -1364) Ice Plains Spikes(-2882, -3283)

And now, finally-

What you've all been waiting for-

The seed of this magnificent world.

-7920986828745015502

Have fun! Let me know what you find!