Truth Social appears to be stillborn mostly due to technical incompetence. Otherwise, it might have been at least somewhat successful in crowding out the gabs, gettrs, etc.
I believe Musk would hire the proper talent and wouldn't screw up a launch this badly.
Perhaps but you're talking a year or more of building. Also, while there are plenty of Muskboys on HN, I don't think he has the star power that guarantees success, so it'd have to be something more than just "Twitter without moderation", resulting in a pretty long lead time to alpha v1.
More likely he would just buy a different platform, since many of his companies he hasn't created from the ground up.
I believe Musk would hire the proper talent and wouldn't screw up a launch this badly.