If you continue to ignore him and try to open it eventually you will open it and find a Cursed Medal. The Cursed Medal will make rupees and hearts show up more often as well as enemy treasures. However it comes with the price of not being able to open the Pouch menu. This is especially bad when you need to get the special water for Faron the water dragon since you can't use bottles.
you can either find it in a chest rarely or go to the bamboo island in skyloft and get a high-ish score
They are mainly inside the chest that are activated through godesse cubes, but you can also get one by collecting gratitude crystals for Batreaux
depends... WHICH CHEST!?
all you have to do is fined a chest get to it's front and push A to open it
shoot it with your bow
You will need a few bombs, throw five near the chest. after that reach someplace to fire the boomerang at the chest, then trow the boomerang again and the item will come to you!
you roll into the poll/wall
You don't get the mirror shard from a chest. You have to defeat a boss to get a mirror shard.
when you buy the wooden shield, put it against what you want to defend from.
get the boomerang.
The big key
A spirit gem