Rejuvenating Water: Just change damage amounts healed to match current C-rank damage; the -.5 rank is ehh to me now. You might be better off just having a pre-heal effect the same potency as the heal.
Kidney Coldemnation: Leaving this, as it's my own technique.
Ice Prison: Detail what is needed to break it/get out (it should be easier to escape from within than to break through as a defense).
Cold Sky Water Attack: Detail piercing depth of senbon.
Archerfish: This jutsu scales with the user's rank; however, D and C-rank on here are grossly underinflated and higher ranks are overinflated. That being said, I think somewhere near 50-75 cubic meters would be good here? (keep in mind 1 acre ft is 1234 cubic meters.)
Ice Disks: Just say what can break them (and if used for defense, if one breaks does the jutsu get undone?).
Ice Spears: Are these actual spears or do you mean like, stalagmites/spires of ice? If one spear breaks, the jutsu's dispelled. 6 is too many, methinks; 3 or maaaybe 4 is good.
Ice Encampment Wall: Make it so that blocking 1 rank higher becomes buffeting to 2 ranks lower in damage.
Blizzard of Blood: Reduce the radius in accordance with jutsu rules; since this has a weakness, you can go slightly bigger.
Flash-Freeze: I feel there should be a miniscule delay between getting in range and starting to suffer the effects. When do these people thaw out? Is the freezing immediately undone when you end the technique?
Sternum Shatter: Can you reword 'stun'? The default is being unable to take any action at all (which is reserved as the power of an A-rank jutsu).