Well as I mentioned, all the areas on the map are coloured and revealed when you go from Faron Woods and dive into Floria. You really can never know ZFG
Yes you can, I bet many people here completed the game with some statues missing.
I noticed that I were missing like half of the statues when I completed hero mode, so I had to run around and get them.
The reason was because I rushed through the game, and didn't bother saving, so I didn't interact with statues at all.
And why would all statues even activate, there is no reason for this at all. They are supposed to activate when you interact with them, just like in majora's mask. (yes, I count attacking them as interacting in MM)