>Problem B:

Duke. A more technical answer can come from Michael but you may have to wait while he is at siggraph. I would say those are not curves and wont show up in any kind of render of the model. I think they are construction seams. They get created by how things are built and sliced up.

Just a note as I read your construction methods. maybe try a little different to get a result you want. Draw your box as a solid then boolean diff the holes, then fillet what your after.

Here's a file to look at. Post a file if you're after something different.

Burr