If one of the cards has all three battle icons, do I still put the others into my hand?
[Source: WotC]
Yes. The cards will all be put into your hand if their combined battle icons include at least one white, one blue, and one orange.
What happens if I play this with 1 or 2 cards left in my deck?
[Source: WotC]
You’ll reveal the remaining cards of your deck, then reshuffle your scrap pile. Then reveal cards from the top of your deck until you’ve revealed 3 total cards. Then put them into your hand or scrap pile, depending on their battle icons.