You do know most of those situations will present themselves like... never... right? In all of them you already start at +1 and with a Sub, and considering things like Registeel should be switching out of this set and not in, that makes those calculations even more absurd. From a more realistic point of view, this is what would happen:
Milotic: Shouldn't even be switching in as, IIRC, it's 2HKOed by Thunderpunch, or close to that.
Registeel: Really...?
Venusaur: Again, lowsy switch because of the high amount of damage it takes from Ice Punch. However, given the fact your opponent is completely out of counters and decides to bring Venusaur in, if you get a Sub as it switches in, you still won't beat it, as you haven't Bulked Up.
Arcanine: No Bulk Up no deal OHKOing this, and you have neglected Intimidate.
Rotom: Without Bulk Up it'll never be 3HKOed, which means you'll eat a Burn or die due to repeated Thunderbolts.
Milotic: Shouldn't even be switching in as, IIRC, it's 2HKOed by Thunderpunch, or close to that.
Registeel: Really...?
Venusaur: Again, lowsy switch because of the high amount of damage it takes from Ice Punch. However, given the fact your opponent is completely out of counters and decides to bring Venusaur in, if you get a Sub as it switches in, you still won't beat it, as you haven't Bulked Up.
Arcanine: No Bulk Up no deal OHKOing this, and you have neglected Intimidate.
Rotom: Without Bulk Up it'll never be 3HKOed, which means you'll eat a Burn or die due to repeated Thunderbolts.