Are we sure there isn't some single market principle that overrules the presumption that you'd have to register in every country? AFAIK generally you're allowed to operate in one country and sell things to other countries, under some principle of single market / customs union.
Yes for this there isn't, strange enough. I don't know why either. I read that part of the issue is that the EU still considers part of the waste policy a national sovereignty. But I don't know enough about that to verify that.