The paint textures are dry oil brush strokes from Painter IX, if you think about my latest Maedhros versions. This soft mimics traditional media well. (Though I have never tried to paint with traditional oils.)
There is not so much of Mandos in the Silmarillion, so if anything in BoLT was not corrected in Silm or HoME, then it is still canon. I need to peer to the information about Mandos, for I was writing an essay on Valar's look for my friend's web page and it would be good to add more to the Fëanturi's description.
Russian - I've been learning it for 3 years, but never really learned. The orthography killed me. I've been learning German the same time, I was better on it, but I wouldn't be able to talk in German now. Pity, I can speak only Polish and English, I should learn something more.