Greg responds...

1. I don't think I've worked that out precisely.

2. Um... he liked the look?

3. Nightwing, Aqualad, Kid Flash, Superboy, Miss Martian, Artemis, Zatanna, Rocket, Tempest, Aquagirl and Troia were all members when Jason joined. I'm sure Red Arrow probably met him at some point too. Though I know the general time period, I have not yet nailed down the exact date of his death, so depending on that, it's at least possible that Lieutenant Marvel, Sergeant Marvel and even Batgirl and Bumblebee knew him too. But maybe not.

4. Okay, (a), who says they didn't try? And (b), who says they haven't held that out as an option for later? Or, given that they had info on multiple heroes, maybe both. Keep in mind that Ra's has known Batman's secret identity for some time, and has chosen not to use that information against Batman. And keep in mind, that the Light often uses the heroes as pawns in their plans. Destroying their lives is only useful if it's useful. The Light isn't out to GET the heroes. That's not their raison d'etre.

5. The Reach did a slow take over using multiple tools, (including the Reach drink and others), until the Earth in essence put them in charge. At which point, things sped up considerably, and the Reach murdered and enslaved the populace and stripped Earth's resources, etc.