Ah OK! I missed the image of the cutoff dialog...
It must be due to your system font preferences because all the fields are visible with default fonts.
But even if you can't fix the font you should go ahead and create your plugin package with just the Flex project. Then you can copy manually your service jar file in the /plugins directory that was created.
/tools/scripts contains a package-plugin script if you are interested.
Once you get familiar with the environment you can create your own build scripts tailored to your system.