Quote from Sopha:
It has two parts. First you go towards the candle in air and divekick with neutral down, rather than forward down; it should still go forward
Ahhh, this is the part I was doing wrong, I didn't use the "neutral" divekick to hit the candle. Now I'm getting these launches, thanks!
You're right about the ending. If you have all furniture, Lydie will lean against Juste right at end of the good ending.