When you became a Dragon Knight you've gain the ability of "Supra-Dragon-Jump". It's a little hard to take in hand but with experience you can block yourself (with a wall or something like that) or take a 360° rotation for go in a platform. Normally everything in Divinity 2 is accessible with a jump... If you can't after some tries (ten or twenty...) and if it don't seem to be created for that, stop trying immediately ! It's the surest way for stay blocked between two rocks or something like that.
The jumps and falls are good in a special way:
-It's playable, you can change your direction and speed.
-It's realistic, you can't go ahead or go back like you're "flying" before touch the ground. Just like in real life... But in real life you can't change the direction before crash yourself and die... Or just touch the ground.
Divinity 2 don't really need a specific-good-playable-but-realistic-jump because jumping is not the main way for finish the game (ok for Mario but for divinity...). You actually can jump everywhere you need (a lot of peoples finished the game already and even me, finished all the quests). So "Impossible" don't exist for now, just "challenging" and sometimes "optional"... What more can we ask?
You can't target or damage flying enemies if you're a human, unless they attack you first.
You can. I'm became a specialist for killing the wyverns in the sentinel island. Ok you must have a bow or magic and a lot of time.
Just try to see the wyvern, follow here and wait for her to come closer. When you see her name/life just shoot... And repeat until she's dead. (Be careful it's hard, not fun and ... Deadly) The crosshair help much too if you play with.
You can also try in the flying fortress too. The creature is really deadly against flying things (if you give her a "gobelin's head" or a "dragon-elf's head"). So that's not really a problem.
But I'm ok for something: The gravity doesn't work every-time... When a hammer is on the top of a barrel and you crush the barrel... You've 75% chances to see the "flying-hammer" in action, but in truth... I don't really care, if hammers or candle or others want to fly it's not my problem because that's not block me in my way so I keep up and thats all.