[2020] Advice

The brighter it is, the faster the production speed. Not every world has white spots.

Circular means it has a round footprint. It can be handy sometimes.

If I remember correctly Fire Hazard is an on/off setting. If it's 0 then it won't catch fire, if it's 1 it might catch fire. Been a while though, so I might be off. :P I always leave them at the default.