Wind:
Back in the old <v20 versions, servers used to have wind, which affected particles based on their wind coefficient. So far, I haven't seen any wind on maps that affect particles. I would really like to see this feature back in Blockland in the form of a few sliders in the environment controls, much like the ground and water scroll options.
Along with this, it would be nice to see a control for this added to the environment events pack.
Precipitation Density:
In the current environments that we have, the precipitation density is described by the atmosphere file. Unfortunately, this is not customizable from the environment GUI. I would like to see this as a slider.
Events with this would be nice as well.
Precipitation Particle:
This is my final suggestion in this thread: Ability to change the particle through a menu. Some maps come with rain, and if I wanted it to snow, I wouldn't be able to.
Events would also compliment this well.
I would like to see these as default in the environment men, as they seem elementary enough to include.