I am planning on making the file attached below a solid object to be able to export to STL, then into Slic3r, then printed.
I have tried boolean unions after converting the mesh to open/closed polysurfaces. I am stuck on how to properly get everything to one polysurface, I’m assuming?
it is a mesh. a polysurface would be an array of NurbsSurfaces joined together. just to be sure there is no misunderstanding, to print it you dont have to go that way if you dont have to do any nurbs specific adjustment to the geometry.
first explode all parts that you can see what you have.
problem nr 1
your object is only 0.09 mm big, i guess that is even for the finest printer not possible to print, you might have messed something up while importing it. you can use Scale to rescale the object to a more appropriate size.
problem nr 2
in the image below i highlighted a part of the mesh which is not a volume at all, its simply a flat mesh joined with the rest. this one would have to be made into a volume with OffsetMesh
some parts of the mesh can be joined into closed meshes so its not utterly hopeless, still it needs a bit cleaning up and maybe offsetting mesh etc till you can booelan it properly together. use the What command on each part to determine if its a closed mesh.