Okay, I'm going to try and address a bulk of things here since I've rewatched the finale, Origins and I now have Suzuna's DVDs in my possession.
Backstory: Origins
From the looks of the Origins episode, Aerrow's father passed away ten years ago at the hands of his own co-pilot (The Dark Ace). Then we move on to seeing Aerrow getting chased by Cyclonian wannabes! The summary of the episode is Aerrow discovers that he is the last descendent of Lightning Strike (I. I will never take this seriously) and that he inherits the Condor and a Sky Knight destiny to lead Atmos back to victory against Cyclonia.
Now, canon doesn't really fill in much of the blanks here so I'm going to be speculating a lot of how I believe Aerrow lived his life, his ideals, his thoughts on the whole destiny plan and being a Sky Knight.
The only real indication of Aerrow (as well as Piper and Finn's) backstory is this one line.
"We did! We chose sides the day Cyclonia destroyed our families and our Terras! We chose... the Sky Knights!"
From the looks of things, Aerrow was pretty bitter over that fact. I assume they barely escaped those attacks and well... I honestly don't want to think how bad they might have been. I don't think Aerrow's mother was part of the Storm Hawks (and until I get any indication otherwise, that's how it's going to stay) so she might have been living close enough to Cyclonia to get attacked and have the Terra conquered. (And here, I assume Piper and Finn were living on the same Terra when they escaped). I'm not sure what age they moved to Terra Neverlandis and from the looks of the fort, they might have been there a while before the Cyclonian bullies came for them. I also think that Aerrow doesn't spend much time thinking about his family, not because it's too painful for him (it probably is to a certain degree), but because he honestly can't remember much of it! Which suggests he might have made his escape at a pretty early age and fended for himself.
So, where did the Sky Knight thing come from? Well, every person on Atmos knows about Sky Knights defending the Terras and protecting the people and I think when Aerrow lost his family but gained a new one, he really wanted to be one thing; strong. Strong enough to defend the people he cares about, to never let those tragedies repeat itself and strong enough to fight injustice. Which is why he's very oriented on the Sky Knights even at an early age and before he finds out about his destiny. The destiny thing just... kinda clinches it for him.
BUT WAIT! Aerrow found out his father is the famed Lightning Strike! What does that mean for him? Hilariously, he doesn't believe it, he's weirded out, but he rolls with it because... that's how Aerrow functions. Does it have any personal bearing on him? Other than proving he is a real Sky Knight, it... really doesn't! He doesn't remember his father at all! And that's probably why he's not... as angry at the Dark Ace. He is angry at the Dark Ace (grr rival grr) but I don't think he's aware of the exact nature on how his father died. He doesn't know how his father was betrayed. And betrayal is a big thing to Aerrow because he trusts people explicitly.
(this is also why Dark Ace, we totally need a "You killed my father" thread)
In the end, what does this shape Aerrow into? For one, he accepts that being a Sky Knight is his destiny and basically all he ever wanted to be. He takes in his family and makes them his team. He doesn't let being Lightning Strike's descendent affect him much because destiny aside, Aerrow's just going to do what he thinks is right. And if destiny fits to it? Even better.
TL;DR
- Aerrow lost his family and Terra
- He doesn't really remember his childhood
- He wants to be a Sky Knight because a) He'd be helping people b) Stopping Cyclonia c) Never letting the same thing that happened to him repeat itself d) It's the right thing to do
- Destiny has no real impact on him other than "o yeah, I have a destiny"
- Aerrow doesn't know how the Dark Ace killed his father.
BONUS - Who thinks Radarr is secretly from the Far Side of Atmos? Anyone? Or is it just me?