"Tectonic Activity" and "Pollution" modifiers somehow from a planet that's already Terran? Will the MUD solve that for me?
"Tectonic Activity" - NO. Same thing is to a "hight\low gravity" and "no light". You can not improve that.
"Pollution" - YES. You do not need a MUD to do this. "Atmosphere Adjuster" structure will do the job. Slow and costly, tho'.
Advice: you do not need to hunt "perfect" system. Hazard modifiers are no more than small upkeep increase. Hight "accessibility" grants huge income, able to overlap even 275% hazard rating penalty. Besides, it is boring to have all the planets of a same terran type. Where would you seed lobsters? Just choose "good enough" system.
I am aware of all that, of course, but WHAT IF I set up my colonies then one cycle later I find an even BETTER system? That thought doesn't let me sleep at night, I tell ya...
As for the "Dark" hazard, we are getting artificial suns in the core game next update... I can't wait for 2025!
"Tectonic Activity" honestly makes no sense to be logically fixable, which is something I hate because I'd love if terraforming provided a logical (if expensive/tedious) solution to every planetary hazard. How would you realistically stabilize a planet's tectonic plates though?
Same for gravity (I absolutely HATE "High Gravity", it ruined more than one terran world for me...). I imagine some kind of planet-wide, giant gravitational stabilizers wouldn't be considered more space magic than we already have?
Maybe, ultimately, for balance reasons, terraforming shouldn't eliminate the hazard conditions but reduce their hazard rating by some amount, like -15% or -10%? In lieu of this mechanic, it would also be cool if the already existing terraforming methods didn't eliminate the hazard outright one day, but reduced its hazard rating steadily over time. So, for example, the pollution doesn't just evaporate one day, but steadily decreases over the cycles.