Just curious, as I haven't gotten one yet, but does terraforming the biome of a planet change its threat level? I am hoping it doesn't, because I want to build a colony on a high threat-level world for the better tenant rewards, but I'm not crazy about the way a lot of those high-threat biomes look.
It does not. Terraform a scorched planet into a lush planet and you end up with a tier 6 lush planet.