1. Backwards long jump. If you want to see people doing it, Google it.
2. No, it's actually this:
Boost into a slope and jump at the right moment and you'll be launched forwards. If timed perfectly you can get some insane momentum by doing this.
It also works with flat surfaces, but it's much harder to do. Your feet will have to be level with the tile you want to boost launch on, then boost into it and jump at the right moment, which should be just as you come into contact with it.
I can't really give you any better advice about exactly when to jump. You just need to practice a lot and you should be able to get it into muscle memory eventually.