Did you think about adding a "Recent Directories" history into the file and directory dialogs?
When adding libs the the compiler options it sucks to navigate to the directory over and over again.
Yes, why not add a combobox there? Where you could simply copy/paste, and if the directory is invalid, it doesn't let you click ok. :)
No, wait, WHAT AM I DOING? This should belong in the FEATURE REQUESTS! Guys, see the "Request a feature" link on the left?