Guys, you need to think...um...inside the box. You don't need a whole new graphics layer for magnetism. Just keep the magnetics inside the element code using normal interactions. As for fluid magnet...would be useful if you had magnet wire to generate electricity with it. (would spark when liquid magnet flows past it)
I honestly love the idea of Ferro-Fluid. But I can't think of anything I would use it for. Maybe as a sub for Mercury because it wouldn't change its volume due to heat. But still a really nice thought.
MGNT - REPL set to work on only metal bits :P
And don't make ferro-fluid conductive, that could ruin it's uses.