Apologies for the vague title, I knew of no other way to describe.

Say you parent theme and a sub theme, both omega-based. (so the theme is alpha->omega->parent->child).

In the parent theme, you have the following css:
parent-global.css
parent-alpha-default.css
parent-alpha-default-narrow.css
parent-alpha-default-normal.css
parent-alpha-default-wide.css

In your child theme, you have
child-global.css
child-alpha-default.css
child-alpha-default-narrow.css
child-alpha-default-normal.css
child-alpha-default-wide.css

There are a few things which I find confusing in this setup:
1) With the exception of the *-alpha* css files, you have to explicitly include every css file from the parent themes in a sub theme. They don't pick up automatically. So, for example, if you were to go to your parent theme and rename parent-global.css to styles.css, suddently all sub themes of this theme drop that stylesheet, since it is not explicitly included
2) The parent/child-alpha css files do not operate in the same manner as the global css files where you have to explicitly include them. How do you exclude them if desired?
3) having to explicitly add every theme stylesheet into the info file adds unnecessary bloat

I don't understand omega enough to know if this recommendation is reasonable, but what about including all theme stylesheets by default and choosing to exclude them one by one.

In fact, the same goes for the module css fiels in the exclude css section. Why not only output a line if the css file is actually being excluded?

I think the highest priority for me is to make a parent theme configurable (for example, changing a stylesheet), while not having to make a similar change to every child theme.