A: I don’t think they’re intended to be used on furniture. That being said, you could try warming it with a hairdryer or using something like Goo Gone to remove residue, depending on the finish of the furniture.
A: Yes they can. It has a sticky back, but doesn't adhere to wall permanently so you can move all over to see the sample in different lighting and rooms.
A: Yes, you can move from one wall and restick on another.
A: Not sure if it would peel off well. I attached it to porcelain tile on my fireplace and it was hard to remove. But it did come off and did not leave any residue.