Well, I did some testing earlier today. Learned a few things, had some successes.
First, never touch the warhead with your ship. Leave at least one block of distance between the warhead and your ship. Accidentally moved JUST as I launched, pointy part of my fighter tapped the warhead, BOOM, missing that pointy bit. Drink more caffeine if you find yourself too jittery.
Secondly, always make sure the push effect computer is facing the direction you want the torpedo to go. They can, and will, go sideways if you put the computer in wrong. Pro-tip: Select the warhead with F, be sure to ctrl-c the phrase "/destroy_entity", fire torpedo... if it is going somewhere OHGODNO, hit enter, ctrl-c, hit enter. Bam, wayward torpedo is gone.
Thirdly, torpedo design. Your design is okay, Dr. Whammy, but I have made what I consider to be an improvement. Your mileage may vary. I found that the torpedo will often still be mostly intact. The ship cores are impervious to damage, and typically everything behind them survive. However, if the push effect module and computer survive, you will end up with that piece careening off into space. And they are next to impossible to corral and recover. So I suggest this design.
FRONT [warhead] [push effect computer] [push effect module] [ship core] [NOT signal] [power] [DELAY signal] [rail docker] REAR
What happens is that the warhead impacts and explodes. The push effect computer and module are destroyed (as opposed to the NOT signal biting the dust), and the remaining piece of torpedo slowly moves away from the point of impact, making it much easier to corral and recover.
Also, you can experiment with the warhead. Have a + of warheads (a central warhead plus one up, down, left and right), a couple of hull blocks, then a second + of warhead, and so on and so forth. Unless the object moves (and I found out that even a 10 x 10 x 10 cube of advanced armor will begin to move after the first impact), the torpedo will continue to bump into the target, exploding successive warheads.
Thanks for the help folks with my foray into torpedo design and experimentation.
:D