Wait what?
Yeah, that was rather poorly stated on my part - plus these were statements quite a time apart. I think Imp caught the jist of it, though. I'll clean up the wording in a little bit.
Graphics set replacement is totally fine as it has no impact on game play. Any gameplay affecting mods not approved here are forbidden - so no 0 speed dwarves, no changing damage/damblock, nothing like that. (I'm leaving the door open to some minor adjustments to the mods that fix gameplay - but they need to be approved here so everyone can use them. Who knows if Toady gave groundhogs a damblock of 10000 or some typo like that that escaped testing. We're all familiar with the cat fix, even though that can't be applied retroactively.)
I'd suggest renaming your save folder to your fortress name. That's what I do in these challenges. I've never found it confusing in previous rounds. I'm really hoping DFMA will be working for this...
Question regarding rule #6: does this apply only to above ground, or to underground features too? If we breach an underground layer or HFS, are we allowed to wall it back up or must we leave it open?
Underground features as well since this version presumably exposes the underground to be a peer to the surface. More specifically, at any given time the majority of your dwarves (including non-military) must be able to path to ALL exposed map edges including the bottom of the map, except when blocked by natural features. That doesn't prevent having some dwarves locked off somewhere like in a lever room or something like that, but if some nasty wanders onto the map from the side surface, the side underground, the magma pipe, underground river, HFS, whatever - they must be able to motor in and massacre the majority of your fort. You can cage them, put traps before them, and all sorts of things - but you cannot block them outright using constructions.
This leaves more than a few loopholes to accomplish the mining task. Use them wisely.
Solifuge added as a player.