Well, the main problem with making mods is compiling and getting all those dependencies. So since the powdertoy is sorta written in C++ how hard would it be able to edit the source (specifically particles) while in TPT? let the flamming begin..
Will you add a feature in a future version of your mod that will let you save to a file, element changes and additions so that when you next load the program it will also load your new and edited elements?
On a side note, I know LUA console has many more possible commands (even without modding) than the previous console (which just let you set a few variables). What are the new features that became available when LUA version of the console was introduced?