Whether a song goes "lounge lizard" or stays true to the original groove I think depends more on the style you choose and the way it's sung. More so than the key you choose to sing it in.

If you take Bad Moon, and apply a smooth jazz style.... you got instant lounge lizard grist.

You can modulate all over the place and still have that original groove if it's played with the attitude, groove, and feeling JF put into the original.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.