[Fantomen]

1. That would depend on the strength and temp scale of the dominion in the province, as well as other things that affect temperature shifts, like sites, season and a few special units. Generally speaking if you WW the province to cold 3 and there is no strong heat 3 dominion to shift it then it would still be cold the turn after.

2. 7 armor negating damage + DRN is a LOT more than it sounds. If the province is cold and the units not cold resistant you'll do a lot of damage. But since the spell is very expensive and only targets half the enemy army that is only really worth it against a big army with lots of human HP mages IMO, most of the time I would spend those water gems elsewhere.

3. Testing @ dom3mods indicates that the sieging army is always targeted (enemy 1), but there is anecdotical evidence to the contrary. Like every scientifically schooled person knows, anecdotical non-reproducable evidence is worthless. So I assume the tests show the the truth and those spells always targets enemy 1.