I agree with a lot you said, I do disagree with a few characters, but great choices.
Wonder Girl and Batgirl really stood out to me in the first half of the series, especially in the all girls episode. Bumblebee too, and in the War episode she solidify her position in my eyes.
Lagoon Boy I felt is season 1 Superboy, where he's arrogant and a hothead, given the time and development, I really think Lagoon Boy could've been more like season 2 Superboy.
Captain Atom had presence this season too. probably the only Justice League member that did. Black Lighting was a huge disappointment to me, he's one of my favorite Leaguers and he was essentially a background character like much of the Justice League characters were this season.