Looks somewhat like Dart, but I do not know much about it - is it Dart or really something you cooked up yourself?
I don't really get the question. Do you mean the language? You are posting in the setup tool's thread.
In any case, both have nothing to do with Dart, the setup is written in Kotlin, the compiler in Java and we started Wurst before Dart was announced.
Ideas and concepts have been taken from all sorts of languages.
All of this info is easily publicly available since open source
WurstScript