Each time you cast Haze of Rage in a turn, its storm ability will trigger. Each spell you cast before it will be considered when determining how many copies are created, but previous times you created copies of a spell will not.

Haze of Rage affects only creatures you control at the time it resolves. Creatures you begin to control later in the turn won't get +1/+0.

Spells cast from zones other than a player's hand and spells that were countered are counted by the storm ability.

A copy of a spell can be countered like any other spell, but it must be countered individually. Countering a spell with storm won't affect the copies.

The copies are put directly onto the stack. They aren't cast and won't be counted by other spells with storm cast later in the turn.

The triggered ability that creates the copies can itself be countered by anything that can counter a triggered ability. If it is countered, no copies will be put onto the stack.