Yes you are right is no need of nukes tires i have expected this. But the creatures maybe they just become green and aggressive.
Yeah something like the fatman, and radiation would make certain planets and area's interesting, I like the idea of environments not always being a clean stroll through the forest but gritty harsh area's that effect how well you can fight, and how long you can be in them. Although the idea of taking out entire civilizations leaves a massive opening for griefers, I think something tamed as mentioned "Fatman" would be good. So long as a planet with the materials to make nuclear weapons contains radiation, and refining said material would have to be in a contained environment to avoid catastrophe.
I know and understand, but it depends on the developer as well. I do agree not to use nukes, but if it come to the developer bring nukes into the game, then we have to make discussion about how many and what is it going cap to that, making or stealing nukes is not going rub off form the game play.
Reading this, I guess we need a Biological Weapon Convention, a Chemical Weapon Convention and also a Nuclear Weapon Convention
Hmm. . . If the impacts of radiation sucked enough, (the radiation spread from the site, it damages/diables electronics in the area, the radiation will eventually decay but before then it's going to wreck your shit, zombies and mutants will spawn, and you're going to have to make a Chernobyl-like cask over the crater, armed with super-expensive radiation-proof turrets on the inside to keep the zombies from nomming their way through the wall.) But a nuke's capable of one-shotting a medium-sized boss (With an additional expense that any items dropped will be vaporized.) you might think twice about using it, because the problems that it's going to cause for you might be worse than killing the boss yourself. So you're essentially trading one bad thing for another bad thing and hoping that your choice will ruin your day slightly less. As for the greifing potential of a nuke; they can always be disabled/nerfed on servers or protected against. Someone might try to bomb you, but that's why you built the orbital defense platforms in the first place. To prevent nukes from landing.
I like all things nuke-y, but for this game I'm not sure it would work. Perhaps there could be a "destroyed world" biome that has already been nuked (previously suggested). Also maybe a weapon that eradicates the planet once it has been depleted of resources, thus removing it from the map? Although this may be a bit much.