1) lern2english
2) It's a DVD, not a CD. Call it a disc if you feel like being ambiguous.
3) To actually answer your question... no. Once installed, the homebrew channel doesn't require the Twilight Princess disc to run. Howevery, of course you will need TP to install it in the first place; I personally chose to rent it for a day.
And lol Twilight Quest sounds like a good name for a new game.