Some NW mechanics questions

Grenade doesn't work well in Aqua, it just looks cool.

If you just tap the key, the bomb is simply dropped onto the enemies. Sure, it wouldn't be good for hitting squids a few platforms over, but it would be VERY easy to hit squids below you without putting yourself in danger. Not to mention that you can casually mist really distant platforms: you can drop a bomb from the top left and hit squids two-thirds of the way down the map.