Can someone tell me what effect setting the swc files in the sdk folder as runtime shared libraries in a project via the Library Path in the Flex Build Path. Does setting these as runtime libraries have an effect on a project or is it just setting the framework as a runtime library amend the final movies file size?
It will make your SWF size smaller which should reduce load time and bandwidth costs. You may need to change your code as using RSLs may find places where you need to specify a ContextualClassFactory instead of plain old ClassFactory. Those usually show up if you use embedded fonts and find they aren't working properly.
Flex SDK Developer
Adobe Systems Inc.