Is it possible to make opus the default browser inside other programs. I save a lot of files from Outlook email but I would have to navigate using windows explorer when I hit select "SaveAs". Also inside of Delphi when looking for images on buttons.
No.
The closest you can get is to access your Opus favorites in the default Load/Save Dialogs using http://resource.dopus.com/viewtopic.php?t=1251.