Yes, the Delete key is disabled in Finder (let's not even get started on that POS). You can get around this with KeyRemap4MacBook (a free utility); there's an application-specific mode so you can make the Delete key (the real one) send stuff to the trash when Finder is active. The only problem is that it can't tell when you're renaming a file, so if you hit Delete while changing a filename, the file will disappear to the trash.
KeyRemap4MacBook can also correct other deficiencies, such as making the Home and End keys go to the beginning and end of the current line instead of the entire document.
I dug up an IBM Model M keyboard the other day and got an active USB adapter for it (passive ones won't work). Despite the lack of any key to replace Command (since these '80s keyboards don't have a Windows key), I set the left Alt key to be Command with KeyRemap4MacBook, and it works great with my iMac. I even have the Pause key controlling iTunes stop/start and Ctrl+arrow keys doing track selection and volume.
Haven't done anything with Scroll Lock yet!