When applying fades to video or audio in Sony Vegas, you may need to adjust the speed of the fade. To adjust the Fade Type, right-click the fade and under Fade Type adjust the curve of the fade. You can also right-click when hovering over the fade offset to bring up the Fade Type menu directly. Different types of curves will give different fade speeds so be sure to experiment with the different fade types.
You can limit the files displayed in the open dialog to quickly access particular file types. In the dialog window, simply choose a file type to display in the Files of type area. For example, if I only wanted to view all the Vegas Project Files (.veg) I can choose that from the list of file types and only view those files.