If you have FileMaker advanced, you can create a custom menu where the delete action does not have a keyboard shortcut.
With regular FileMaker, you can use Manage | Security to disallow deleting records from the layout's table. You can then put a button that runs a script to delete the record on your layout and set it to "run with full access privileges." The result is that the keyboard shortcut and menu option in Records no longer works, but you can still delete the current record with a mouse click on the delete button.
Thanks Phil. I have yet to try creating custom menus but the time has come for this as well as a couple other reasons.