Well, I DO have trade access to steel and pig iron (humans and elves rarely survive in my pocket universes), but I intentionally embarked in a metal free area in a metal scarce universe, and I've decided to use only goblinite (and adamantine), with the exception that i buy crap metal (like gold) from caravans to satisfy strange moods and any special noble demands [the bronze bed for the mausoleum requirement in my previous fortress was unfair, in my view]. The goblins bring copper and silver, while the undead brought bronze (long time since they showed up last, though), and sadly, no kobolds. And I've actually gotten hold of a huge amount of adamantine (>1500 wafers), but then I've already reached retirement time (don't think there is anything of interest left to do: the goblins do not seem to advance in their sieges, just the same donation expedition once or twice a year. The caverns are gummed up by excessive tree growth and camping critters. The clowns have stopped rushing to their death [well, there is a bunch camping in my clown connection tunnels]. I think I may have used up all titans, and it was a long time since I saw any FBs [I did have 5 at the same time once, though]).
I've never explored magma pistons, but have minecart and impulse ramp experience (100+ level roundtrip tracks in two different fortresses, plus a rail gun that never saw use in a previous fortress), as well as magma and water pump stacks.