First of all, you don’t need Python to build stdlib. Just use the stdlib-fpm branch which is automatically generated. If you depend on stdlib using fpm, that is what will happen. Currently we don’t have releases for stdlib, but once we do, we would distribute tarballs that are preprocessed, so no Python dependency. Update: I should clarify that there are no Python dependencies for end users. However, if you want to develop stdlib and send patches to it, then you unfortunately need Python.
For your other points, see also this thread: