I know we are talking about the SkyRaider, but my Dad was an A-4 pilot and he said that they did indeed practice the "toss" bombing technique for use with tactial nukes. He said the nuke attack profile for the A-4 was sharp pull up and at a certain angle (I forget now, but I think it was 60 degrees) release the bomb, and split-S to egress as fast as the thing would go.
Needless to say, Dad said he never thought that it would have been a very usefull operation (especially for the A-4 pilots), and it was more a result of the first decade of the Cold War where every attack plane had to have a nuke capacity regardless of its practicality.
Werent some tactical nukes fitted with parachutes to give the planes time to egress?