Sorry for that. At first I tried to split the questions but later thought it would rather be seen as a spamming. I should have asked it first though.Johannes_B wrote: Having multiple questions in one thread is a bit fuzzy and even more confusing for future users on the search for a solution. Can you split the questions to separate topics? Makes it a bit more clear for our LyX helpers as well.
My questions are divided into two categories; (1) basic LaTeX/Lyx (2) LaTeX/LyX support for Korean letters. Most of (1) are solved thankfully. I'll try myself more about (2) (what settings-langauge does, why Korean letters are not supported while using some fonts, still letters inside the menus are translated into Korean).