(This question would probably be better served for users.rust-lang.org; it’s definitely not a language design post.)
1: No, and probably not for a while (unless someone pays people to make a macro attribute based system).
2: Unfortunately I’m not sure what this is asking. If my posit is correct and it’s related to a formal model/definition of the language, there doesn’t exist anything yet but we’re working on that. It’s far off but the groundwork is being laid as we consider the requisite hard questions as a community. For now, Rust is “what rustc does”, and everything else is non-normative.
3: This should be answered on the main website https://www.rust-lang.org. But Rust is an imperative language with functional leanings developed as a “systems language” but can be used effectively in any application domain, especially (but not in any way limited to) the 2018 “featured” areas of Command Line, WebAssembly, Networking, and Embedded.