Lightning Lord is definitely the most interesting villain. His redemption in FYL was perfect (and his attempt to intervene with Roxxas).
Are you recapping from memory? That's amazing. I can't remember the plot of this stuff twenty minutes after I read it. I'd never say that plot was not one of Levitz's strengths, because he was revolutionary. I will say that his plots do not age as well. I just reread the conspiracy storyline, and when it's not drabbed out over the course of months and you already know the ending...not exactly compelling.
I do like the way that fighting induced SGs labor, nice touch. The Validus thing...never really sure if that was a retcon or an old plot device, but it sort of works. I just went back and reread the issues in question, no, there is no mention of mystic lightning there.
To be precise, Validus is plot manipulation of the grossest sort, but the end result is so cool that I forgive it. I consider this giant telepathic electricity monster to be adequately lampshaded.
Also very nice details with Element Lad's tendency to panic and change his mind, which I'd never really noticed before. It's very constant.
The Shvaughn/Sean thing soars untrammelled over retcon status and becomes a fundamental point of character. The best parallel I can see is when Isaiah Bradley was added to the Captain America canon with Truth, not so much a retcon as a righting of ancient wrongs. The lack of homosexuality and TG in LSH is, to modern eyes, extremely suspicious. I agree with J. Shooter's assessment of Element Lad.
I think Tyr thought Radiator was only slightly less dumb than Radiation Roy. I also suspect a typo in his origin, BTW.
Dawnstar is completely awesome, in spite of her embodiment of the Magic Indian trope. Her design looks great, and her powers are goofy but awesome. I was really curious to see what she would be like post-Bounty. Her relationship with Drake was in no way impossible -- it was Drake who made it impossible, with much moaning and gnashing of teeth. You telling me they don't have dildos in the 31st century, Drake? Or is it your pleasure that you're so fixated on?
I would like to have seen an intelligent treatment of Dawnsar, Wildfire, and Superman's perceptions as they approach the speed of light.
In my heart I can't really call post-Giffen LSH continuity. I suspect a lot of people feel the same way about Star Wars. "Mitochloridwha?!?"