We should probably leave the space out here and let the printf string handle the space.

This should probably be indented.

I think bits per pixel and frequency both default to the values in their blend files.

I don't see any change here, other than some whitespace. Whitespace changes should probably be left to their own patch unless you're specifically fixing whitespace.

It looks like you're already adding "new" errors for the window and fullscreen parameters, so we might as well add this one too. Old scripts should be simple to update (and I don't think there are many that would require an update because of this).

I have added blocks { } to the cases and the comments in the same line so that the switch can be folded in QtCreator for easy viewing

removed this because 'no stereo' is already set as default int the declaration of 'stereomode'

I did not touch the space, I only added '[ ]' because -c is optional

224 has no \n, so 224+225 shows up as one indented line, but it was to big to fit in the code.

Everything defaults to the blend file. I wrote this in 216.
What I meant is that, if it was not changed in the blend file, then.. that is the default.
Something like line 236 is more clear?

As I added blocks to the cases, and this one already had a block, I pulled this block one tab left as it affects less lines than pulling all the other cases one tab right. I don't know why it only registered the indentation change in this line. Because it is a comment, maybe?