Alright, back from my Thanksgiving vacation. I'll add the agree/disagrees to the post, plus edit out the cold resistance. Space travel without gear still provides radiation resistance, right?
Other than than, yeah, Discord is canonically just playing through the "story" of the series, with
pages like this, and arguing with the editor there. The card game, and RPG don't contradict the canon anywhere, and simply give stats, and explain abilities. Discord having precog and retrocognition should already be incredibly likely, since he's shown the ability to go forwards and backwards in time, and his
first shown dialogue is him knowing who the Mane 6 are. So Omniscience is also likely using just the show, but the RPG just state these things outright. Examples of him not knowing certain things can just be explained away as PIS.