I prefer permanent DST because my waking hours aren't equal before & after noon: I'd rather have an hour of sun at 6pm than at 6am (before I wake up). But like you said, just pick one and stick with it!

A free neutron can decay because its mass-energy is greater than that of the resulting particles, proton + electron + antineutrino (and because it meets a few other conditions). But the binding energy that keeps a neutron in a nucleus is negative (and therefore the mass of a nucleus is less than the sum of the masses of its constituent protons & neutrons). If the neutron decayed it would violate conservation of energy, and therefore it must be stable.

However, in some neuclei the energies work out such that a neutron can still decay! We call those radioactive isotopes. For example ^(14)C decays into ^(14)N by emitting an electron+antineutrino and changing one of its neutrons to a proton - sound familiar?

Matt Strassler has a good article on exactly this topic, which also links to his articles about particle decay in general: https://profmattstrassler.com/articles-and-posts/particle-physics-basics/mass-energy-matter-etc/the-energy-that-holds-things-together/neutron-stability-in-atomic-nuclei/