Currently it only outputs PDF, PNG and SVG. The next release will have preliminary support for HTML. This will be a structured output so from there it will be easier to support other formats either directly or in post-processing e.g. through pandoc. Pandoc itself supports Typst input but I'm not sure how reliable that is.
Don’t know either, but some things are unrepresentable in the pandoc internal format. It can internally represent an intersection of all its supported formats.