Okay, Keiko-san.
Yes, karaoke and reading the lyrics does improve all aspects of learning the language. It helps tremendously with your pronounciation, bringing it closer to their native style of talking. Reading and writing are also improved because the lyrics help you learn more words, their meaning and the different forms they're used in. Kanji is the most difficult part of the whole language, I guess. I often get the complex ones mixed up, or sometimes their meanings get jumbled up. I do need to practise though.
Okay, thank you Keiko-san.