Not gonna speak to Pi, because I don’t speak Pi =P but I’ll drive by your question about languages: short-term, not at the same time. Long-term, absolutely.
Mycroft is only officially supported (by the company) in English, because, so far, only English is fully supported in code. However, the code that makes it multilingual is there, and you can absolutely use it in a number of non-English languages, with varying degrees of success.
In order to use Mycroft in a particular language, you need a few things, only some of which come from Mycroft or this community:
- Speech-to-Text (not made here, but exists in plenty of languages)
- Text-to-Speech (same deal)
- Lingua Franca (parser/formatter library, made here) needs to support the language in question, contributions always appreciated
- Mycroft skills need the correct vocabulary to work in your language (contribute your socks off)
how to make Mycroft truly multilingual, as in, speaks more than one language at the same time, is probably one of the next big challenges for the whole community, because all the moving parts have to fit together.