Yeah I only know about them, because I've taken my fair share of language tests. If you're interested here is a pretty good explanation of each level. These levels are used for (as far as I know) as a scale for every language.
I wouldn't assume that. I would place these in around a B1-B2 level. Which to be on that level means you've been learning for a good while.
Es ist gar kein Englisch Sub xD Is ist bloĆ für āShit Posting", das heiĆt in welchem Sprache ist egal.Honest mistake on my side though, my feed is always bouncing between languages. Sorry if that somehow upset you.
If you want that, then I'd suggest usinh Bussu and Memrise