Modify "Move to Trash" shortcut in Apple Numeric keyboard
You can modify the NSUserKeyEquivalents dictionary in ~/Library/Preferences/com.apple.finder.plist:

defaults write com.apple.finder NSUserKeyEquivalents -dict-add 'Move to Trash' '\U007F'
killall Finder


It also makes ⌦ move items to trash in rename mode, and it makes ⌘⌫ do nothing.

Forward delete is \U007F and delete is \b or \U0008, even though in DefaultKeyBinding.dict delete is \U007F and forward delete is \UF728. The shortcut string format is described in the Cocoa Text System article.