Playing with some subtle mods I've done.

• Subtle remix in ethics.
• New weapons, hopefully balanced
• Can make obsidian spears and handaxes
• Cobalt, brass, pig iron is a weapon-grade metal
• Lead, gold are ammo-grade metals
• Brass, electrum are armor-grade metals.
  (none of this changed the properties of the metals, just allowed you to make stuff)
• Elves have access to brass, electrum, and rose gold. I don't think they will make weapons out of them.
• Entities will use different metals for their coins.
• Other random crap
• Other stuff from other people's mods (more engraving descriptions, nothing game-changing)

Anyways, there's the perfect embark in the SW corner of the map, a volcano by a major river. There's iron, flux, a waterfall, clay, sand, cobalt, silver/lead in galena, zinc, gold, all civs (no tower ;_;), a very small nearby dwarf civ (so your adventurer can always find the place), olivine and cinnabar, other fun stuff I can't remember.