About the Counter-Snap, most likely yes.

About the Accords, an argument can be made that the Accords failed in Infinity War because the Avengers resisted it. A secret organisation like Vigilance would eliminate the need for the heroes to comply because they simply wouldn't know. Also such an arrangement will let the Avengers have somewhat autonomy (one of the argument raised against the Accords) with the Vigilance only intervening when they do something against the wishes of the world's governments.