s.A indeed does not whiff on Raiden, Maxima, Goro (tested).
Is it slower? The frame data from Keykakko says it's both 5F for startup.
He probably means far s.D. While both close and far s.C are 5f startup, close and far s.D are 5f and 9f respectively (according to the Keykakko anyway).
That said, you should probably differentiate between close and far s.D, as they differ in utility. As you stated, close s.D is great in combos due to the lack of pushback compared to s.C. Far s.D is Duo Lon's longest ranged ground normal outside of his sweep, which makes it great for pokes, stuffing corner pressure jump-outs, and HD activations. Though, because it is not special/super cancellable AND -7f on block, it is fairly punishable.
d.C
High vertical hit stretching about 3/4 of the screen. Has too many active frames, although the animation stays there a while, only the first couple of active frames can be canceled, much like you would see in Iori's close C
You probably mean "recovery frames" here. Moves have 3 stages: startup, active, recovery. Active only refers to the frames when a move can hit. Like you said, because the d.C has a 6f startup, it generally has to be done a bit preemptively instead of on reaction, unlike other characters with faster d.C's *coughShencough*
Kara canceling his cl.CD into reverse rekkas
You should probably just refer to it as s.CD rather than cl.CD since there is no property difference between close and far s.CD; the crossup is merely due to proximity.
It's worth noting that both j.f+B (both normal and EX versions) hit overhead, which can be used as a pseudo instant overhead. If cancelled from a j.B, it acts as a sort of double overhead, though only on standing characters. Using this setup, on crouching characters, the normal version will not come out at all, and the EX version will spend the meter but the move will not actually come out.
- First rekka
Fast, really fast.
For reference, the startup is 7f, which means it's not adequate for punishing a lot of "generally safe" moves, unfortunately. You should probably denote frame data when you can (though it isn't perfect, it
is helpful), as it gives a better understanding of move utility rather than just stating that something is "really fast" or "really slow".
Important to note that stopping after the first rekka leaves you at -8f, which is relatively punishable. The reason most people don't punish is due to reaction times and fear of a delayed rekka. Otherwise, it isn't safe or abusable on paper.
Lastly, one thing I'm curious about is your use of "high/low profile". Are you judging this based on just visual cues? Or have you extensively tested this? Without seeing actual hitboxes, approximated or official, it can be difficult to accurately gauge where an attack actually covers without making assumptions.
Overall, a good attempt at a writeup, just needs minor clarification of stuff and a bit of cleanup, then it's good to go.