Yeah samurai used bows just as much as they arranged flowers. It was one of those Bushido things that gave them an organized and cool lifestyle. Zen archery was the thing, shooting an arrow without aiming, it made their style of bowmanship quite deadly when they got it mastered to the right degree. No wasted time, just a shot.

On the throwing knives I've said before they weren't used as well as people would believe. In fact ninja that wanted to use them as effective weapons didn't often learn from their masters, and would need to spend grand amounts of time maintaining their shuriken for that use. Other than that they kept the knives in poor repair and basic throwing skill for diversionary tactics or temporary pain in battle. Not often the kill though.

On the earth, water, sky, ect. thing yeah they gave them very nice names. xB Mokuton-Nature. They used trees and grasses for escape. Like hiding behind bushes or quickly climbing a tree. Katon-Fire. Using fire to escape. Like lighting a stronghold on fire and assassinating through the opposite end while everyone worries about the fire or they typical ninja smoke bomb. Doton-earth. They used the ground, walls or stones to escape. Like rolling into a ball and looking like a rock or clings to a particular wall to look like he is part of it. Katon-metal. Different translation, but it is using metal to escape. Throwing clinky little metal to distract, or using the throwing knives. Suiton-water. Using water to escape. Hiding underwater and using special snorkel tools to breath underneath or to toss a big mass of floating debris on the water and swimming directly beneath it to his escape.

And from what I learned while training for a samurai was difficult it wasn't as hard as training to be a ninja. Samurai training was something that began some time in the early teens, and after it had been fully trained it was up to the samurai to maintain it. Another bushido thing. Ninja were trained from five to twenty and in their secret communities would continue to be trained to maintain their power, for as a assassin society they couldn't afford having a bad ninja like the spread out ronin and common samurai could afford having a bad samurai.

Ah yes, there is another skill that I had forgotten about ninjas, like you mention, fire. They also used flashes of light to either distract the enemy or unfocus their eyes. In that way they were able to escape in the dark without being caught. Well another way anyways. Most would call what the ninjas did 'cheap trickery.' Instead I call the things 'skillful deceit'. Haha