Having any form of practice is a great way to learn. I forget my vocabulary a lot because I don't use the language much. If you like any of the music, I recommend learning from songs too. Since they're slower than speech, you can hear the pronunciation well and they aren't too long, so you can get through them more easily.

I think I read that by sixth grade, they know most of the commonly used kanji. I recommend using a program that teaches you by teaching and combining radicals. If you want to add me, I'll send you a message about it, though they are all written in English, so some of the difficult words might be tough to learn that way.

Yuke is a form of 'iku'/(commonly 'yuku') telling them to do something. "Tondeyuke" is saying "jump up/fly off". As translations go, it can be a little difficult to apply these to one's own actions. So you can think of Buzz Lightyear's "Up, up, and away!" or maybe if someone's nervous and trying not to stare, they'll think "Don't look, don't look!" It's up to your judgement on a per case basis.

Yuganda is the past tense of 'yugamu', so it does mean distorted/warped.

If you want to get an idea of ways yurayura can be used, I recommend taking a look at the translations here: http://ejje.weblio.jp/content/%E3%82%86%E3%82%89%E3%82%86%E3%82%89

So the idea here could be something like: "I'll fly into the shaking, warped sky to get to you"