I think that the specific 'Martial Arts as Artifacts' proposal takes it a little too literally. I'd be inclined to make Martial Arts more un-equipable perhaps with some punishment for having to suddenly re-equip it, or to make hot-swapping in combat impossible. This would have the justification that 'equipping' the Martial Art is more about taking on the proper stances and essence flows, rather than having your body literally reforged. Having multiple martial arts equipped would be possible, but follow the same rules as wielding multiple weapons/artifacts.
The other issues are that it ignores weapon-using Martial Arts, and also makes it so that there's no real reason a, say, Single Point Shining into the Void stylist would want a powerful Artifact sword, or a Righteous Devil stylist an artifact flamepiece. The first issue is easily solvable; make it so that Martial Arts can boost their form weapons as well as unarmed attacks. The second is harder, since letting stat boosts combine can easily break the game.
What I'd probably do is allow a player with both a Martial Art and an Artifact form weapon to do a training project (crafting a Martial Art) to create a variant Martial Art that takes advantage of having said Artifact. This would have the story justification that Artifacts are different enough that you can't combine them with Martial Arts, and on the game level it would allow the new Martial Art to remove the combat bonuses and focus on the other aspects.