That is an impressive collection. I wish you luck with the Russian. I was fortunate enough to find a very nice Russian "language exchange" partner here, so I am trying to learn some too. Unfortunately I have neglected my German, which is a wasted opportunity.
All I can advise here, is, if you want to be a polyglot pray-er, be careful not to get old, because when you get as old as I am, you may let your dimming mind wander from language to language within the same prayer! "and ever o'er it's Babel sounds, the blessèd angels sing...." Mary Emily Kyrie pomilui