@Assalt
It is technically cloud to ground, and I have found nothing that says it's not comparable in speed to normal c-t-g lightning, but I'll try to verify this. Also considering Lesser Dog, a much earlier enemy, can stretch its neck at Hypersonic speeds just from getting excited (yes, this is somehow an actual feat in the game) far earlier in the game, I doubt this would be an outlier.
Spatial: I'm fine with that.
Gravity Manipulation: I mean, he affects SOULs with his other abilities as well, so the gravity manipulation applying there isn't too far fetched. It's also pretty clearly demonstrated, so I'd say it's legit.
Status Effect: The reason few people but Sans acknowledge stuff like this is because he's one of the only ones in the verse who is aware he's part of a "game" being played by some sort of higher, reality warping entity. Along with Flowey and Chara, I'm fairly certain he's the only one aware of the Player's existence and who actually speaks with them. His fight purposefully has him abusing "game mechanics", because those are the rules of his reality and he's found ways to exploit them. But yeah, it can totally be noted to likely only work in the UT verse, which I thought most people had agreed on for years, now.
Soul Resistance: I agree. No idea why it was taken off, but it does help clarify the inherent minor defenses monsters (and Frisk) would have against certain attacks.
Speed: How fast is he shown to be in comparison to them, though? Because that's the main reason his speed is so hard to gauge.
@Skalt
I'm pretty sure this page predates that one by a significant period of time (created very shortly after the game came out), unless someone added some stuff, later on.