The big GS attack can be included, not for the blow itself, but from what we know of LC, he wasn't much for a top 10, in terms of stats, which means that the fact that Ruo and MC were able to hurt him doesn't mean much, probably a lucky strike from someone with 7k~8k would have a similar effect.
As for the rogues, I didn't consider them to be average, they were probably Demon Execution Squad level at least. What makes me lower the supposed power of the transformation is not the fact that Ruo didn't win, after all I know the guys were prepared (I think I've commented on this before), but the fact that Ruo transformed and ended up almost dead without even eliminating one of the rogues, two of whom even got out unharmed.
As for the last point, I agree, my calculations are just estimates of what I've seen. I am unable to predict how much the author will increase Ruo's power when he advances. After all, he needs to do something so that Ruo doesn't take a terrible beating, one way is to nerf Qi Sea, another way is to buff Ruo.