A simple side dodge might work, but you want to abuse the tracking speed. It's constantly moving at you at a fixed rate, so backwards and pure side dodges tend to give it more time to readjust to your position, thus causing it to smack right into you. If anything, it's easier to try and aim your dodge fowards since you have a larger time frame.
As for the knockdown, why else would everyone care so much? I don't think the fall damage is significant, but the damage of ~20 people DPSing is. I actually use it to do a full Slashing High + Shelter Buff spin2win spree, which is enough to cause fluctuations of ~2% in my overall damage if I mess up my SP management at those points. You can also use the window to use your spears/sticky bombs in order to help get the breakoff. It's usually not worth it to try and DPS unless you have ~10k attack at least. I think the dragon has ~9.4k Def.