My friends - I am really moved by your great interest for my concern, especially also by the fact that you gave me my own version of this beautiful song *sniff* :-)) Finally some fame.
Don't worry. I am not intending to create a singable translation. Even a brutal monster like me is shuddering at the thought of that much violence. What I want is only to give a short introduction to what the song is about in order to give the listener a little access to its character, its spirit. Without that or if I only mentioned that this is a love song I would leave my audience alone with the mere acoustic impression but a song is much more. BTW I can't help thinking that the noise level is simply lower when they know what they are listening to even though they don't understand the words.
What I am dreaming of and what I am working on is giving such introductions as a part of the song when I am already playing the music. But that is difficult - ever tried to talk prose while playing a song?
Re idioms etc: Calling a forest "nut-filled" or "butter on cream" are expressions much too charming to not translate them literally, especially when a song does not tell a story but lives from its poetry. Of course this can only be done as long as it is clear what is meant. When I must be aware of provoking a misunderstanding I might even have to consider omitting the whole thing. However, I might get a laugh if I keep the "thousand treasures". Calling a lover "Schatz" (treasure) is quite common in german - but only in singular. A plurality of treasures inevitably reminds one of a plurality of lovers *grin*. Therefore I am of course much more interested in literal translations than in good english. Also IMO the risk of corrupting the meaning of something when it is translated from irish to english and then from english to german too freely is higher than the risk of being misunderstood when giving the literal translation.
Felipa - I do know wild hazel bushes. Outside of forests. However, as I said I also know the difference between irish forests and german ones. The latter are well cultivated assemblies of vertical poles, all trees of the same kind and the same age, often with any brushwood carefully suppressed until it doesn't get enough light to grow. No chance for nuts inside of a german forest any more...
Many heart-felt thanks to everybody again.