So I had an idea. It's a brilliant, terrible idea. The logistics involved would be monumental to say the least, and the amount of dwarven lives lost will likely measure in the hundreds, on account of the vast amounts of magma, obsidian, and cave-ins to be utilized here.
For starters:
Poorly-doodled and poorly-photographed sketch of the basic idea. In case you can't tell, this will be utilizing a series of ground posts, likely 4 or 6. Each post will have a walkway coming off the rooftop, which leads to a nearby floating post of roughly the same size and shape, varying slightly depending on purpose. This will continue, creating a higher and higher chain of these floating posts that could theoretically go as high as I wanted - with some limitations.
It should end up looking similar to a Kinex skyscraper that's half-empty, a series of solid chunks connected by thin bridges.
Each block will likely be 7x7x2 (or x3 depending on how you count the roof). This is for simplicity's sake of mechanics, you can have a single windmill powering 2 pumps directly with no axles. Yes, you heard that right. I want hot and cold running water through this whole thing. And of course, "hot water" means magma. However, I may do the blocks taller and put in basic axles to funnel power within the local block. Cross-platform power transfer would be possible, but not practical or easy, and I'm proposing enough problems already to make this impossible.
Aside from being an architectural nightmare, with running fluids (and thus heavy heavy pressure systems, safety locks, anti-pressure gates, flood prevention, etc), and enough room to house at least 50 dwarves, including private living chambers, farms, industry workshops, dining hall(s), and barracks, I ALSO had the idea to make this purely out of cast obsidian. That's right. As big and impressive as a project as this is already, it will be even moreso as I attempt to cast obsidian in the middle of the air. The exact method I intend to use for the casting can be described in detail later, but in basics it involves casting something too-large, digging away the excess obsidian, and then caving-in the whole mold frame so I don't have to deconstruct each and every bit of wall.
Current plan is a 2x2 embark with a river and a rather shallow depth. Invasions and weather off, but temperature on as I expect dwarves to melt a lot. 50 population cap and some 2 baby cap. Hopefully, if I uncap my FPS I'll get somewhere like 250 FPS until I start the real temperature issues.
Any recommendations or things to point out before I strike the earth - and the sky?