For the fun fact, shockwave do propagate in the interstellarmedium. Most likely a conventionnal nuke isn’t big enough, but we can see the shockwave from supernova explosion, and voyager did measure the moment it left the sun one.
Radiation may be another beast with a well designed bomb, it’s pretty hard to stop neutrons, and they do a lot of biological damage. However, radiation poisoning isn’t an instant dead. Like shoot a nuke, leave. Come back 2 weeks latter and everyone is dying. Radiation could definitely damage electronic but I would assume spaceship designer worked properly, and the humam will be poisonned before the electronic starts to fail. A note though. The 1/r^2 law would still apply and space is huge. Being 1km out of the explosion divides the dose by 100 compared to being 100m away. 10 km away would divide the dose by 10 000. So the death radius won’t be that big.