I would like to to the delete the current line using Shift + Delete
I think ctrl-shift-k (in the Text Bundle) does what you're after ... you can just change the command that runs it to shift-delete if you like.
Or .. if you don't want to override that bundle, you can select that macro from the Bundle Editor window and hit that Plus-plus button you see @ the bottom of the window over there to duplicate it, move it to your personal bundle and change the activation key to the one you like.
-steve