Depending on how the fight goes, it could end with any of them winning. Majestic would actually have an easier time matching Billy because he doesn't have a magic weakness, but Kal can and has beaten Majestic 1-v-1.
Just because he's Superman, I'd say 4/10 for him, with 3/10 going to the other two.
...which he probably wouldn't have due to KMC default rules about standard equipment (he doesn't have it on him nearly a majority of the time, which disqualifies it as "standard"), and the fact that the thread starter didn't specify weapons.
...and not for the rest of his history. I really doubt it would count as standard, last few issues aside. I also don't remember him using it. Charis used her sword against Majestic, but that's about it. Beyond that, I highly, highly doubt the thread starter had that in mind when he made the thread. Better to go the common sense route than to play semantics over a point that shouldn't really be an issue.
He has a respect thread. The best place to answer your question is there.
I'm not sure what energy projection manipulation is, but yes he's smarter than Kal, possibly a bit more skilled, but from most showings we've seen, no stronger and a bit less durable than Big Blue.
That's speculation. Majestic has never had better durability feats than Superman, nor appreciably better strength feats. The skilled/intelligence edge remains with him, however, so I fail to see a massive depowerment.