Creating a subtheme from a base theme: features or bugs check

• As long as one style is defined, styles are inherited. If a stylesheet has the same name as one in the base theme (even if it is not in the same subfolder arrangement), it overrides it. This is intentional (as i believe it is in overriding module CSS files)?
• theme-settings.php is inherited, but in Bartik at least some custom settings are saved directly as variable_set in the bartik namespace. This isn't a big issue but i wonder if there's some way for theme-settings.php to know when it is invoked by a subtheme and to derive its variable_set and variable_get variable names from the theme that calls it?

^{benjamin, agaric}