You are correct on all points about the concrete encasement - Protect the charges, Smash through the dry dock gate, Prevent discovery. On the second point about "mission bonus", I've heard the same thing without factual confirmation of who died, what their rank was. The ship was "crawling" with curious (and "victorious") Germans, but guard units were moving the onlookers back and securing the ship when it blew.

This time in the war, the Brits were basically fighting alone, and had to craft their strategy and use their limited resources skillfully, which they did. They used their brains. Churchill went against many of his commanders who looked down their noses at commando and sabotage raids as something "less gentlemanly" or unBritish - than open combat. Raids on Norway, sabotage in occupied France - it made Hitler nervous, undermined his clarity of thinking (as if he ever had a clear mind to begin with) and tied up a lot of German forces that could have been used elsewhere. Norway alone absorbed over 300,000 troops, that is over full 20 Divisions, that never got released for combat elsewhere.

There are other interesting characters involved in the background of this raid; the engineers and fabricators who developed the adjustable time delay fuses which had to be dead accurate and reliable, and the demolition experts who designed the charges, etc.. These men all began as amateur tinkerers and inventors, shunned by The Establishment, but Churchill saw their potential and set up a research and production structure that brought their products to the commandoes and saboteurs who used them so successfully.

Cheers, - Art