Sounds like a good idea with positive outcomes if the script conversion works smoothly. With the idea of simplicity for users in mind might I make a suggestion, add a color system to the new syntax that will distinguish the command functions from variables like x,y,z and an active syntax error check that can highlight incorrect lines red while your scripting.
Example: rain /p=x,y,z /r=value /d=value /i=value /c=r,g,b/
Like was stated earlier "I read those square brackets like gypsies read tea leaves..", this could help once we get used to it.