3D Truss to 3D Truss and other fun details

I haven't been able to find a good way to make this connection other than with a simple weld, which I'm not sure would hold. It would look like the connection of an OWSJ to an I-beam, plain and simple. Another approach would be to go with something more like this [LINK]. But this would break the HSS member and maybe make the vertical structure more prone to buckling. The closest precedent I could find is Foster's Sainsbury Centre, but his vertical 3D truss does not extend beyond the connection. What can I do? Weld? Pin? Bolt? Bubble gum?

Second Issue. My floor plate is curved along the x-axis, and corrugated steel is not. What can I do to put a a corrugated steel decking with concrete topping on my building? Do I divide the floor plate into trapezoids and have each section use corrugated steel going on it's tangent, or is it possible to have a custom curved piece of corrugated steel rolled just for me?

The same issue arises when I layout the duct work, I have to find a way to curve it along the main hallway.

Same issue with cutting a longitudinal section... Damn curves.

Regarding the curved panels on the side of my building... Acrylic it is.