I'm of the mind that these modifiers should apply slowly over time. Perhaps a series of self-upgrading buildings that replace modifiers over time. So instead of completely negating the Hot modifier it gives a reduced hazard rating that improves over time as the building upgrades itself over time.
I'm also of the mind that planets should have orbital and surface slots that limit how much stuff you can reasonably have in orbit. In the same way a space station gets added to a planet's orbit, solar shades and mirrors should be visible in-orbit. Orbital and terrestrial industries could be differentiated by orbital facilities having immunity to terrestrial hazards like weather, biome, and gravity. Imagine, finding an orbital gas mining platform that can only mine organics and volatiles
As a side note, I believe new products should be added to the marketplace to reflect the idea of active terraforming: Terraforming Liquids and Gases that would be specifically mined from ice and gas giants.
Terraforming should take a very long time and happen gradually, in my opinion. There should be high tech and low tech versions. High tech should be more efficient and effective but walled behind discovery of blueprints while some low-tech versions should be available but very expensive and only achieve results very very slowly.