Hi, I do it in a similar (but a little simpler) way to Om. I import the Flex SDK as a single simple project (no need for multiple projects) and then set that up a Flex SDK for use by other projects. When making changes to the code I just recompile the required sub project (in framework/projects), I usually use the command line for this but you can also use the ant support built into Flash Builder.
Thanks, Justin
