Sooooooo much of that is assumption it's hilarious.
I never said Kun's lightning is superior nor did i even state in any of those comparisons who was superior, I left that to the reader.
Aleema Keto is stated by Nadd to be superior to Ommin, that guy who rag-dolled Jedi(including Jeth) with Sorcery for a living and is stated to be a natural with Sorcery, one of the best during the entire Old Sith Wars.
Kun's spirit is not way more powerful, the opposite is true, he had no Force Energy reserves and thus relied on the energies of others to do anything at all (random spacers beat him the first time he woke up).
Every time he did do something he would lose his energy... Vodo even says he has to be beaten before he returns in the flesh... where he would be most powerful.
Feel free to read my respect thread, containing quotes on the matter.
Vader has shown time and time again to have large access to much Sith lore freely, his citadel on Vjun contains a massive trove of lore, using Sidious, the lone exception to all rules regarding such things is irrelevant.
If you seriously believe that the ONLY thing Kun has over Revan is the Suncrusher feat then just wow...