If you mean when it opens in kakariko village it is after to beat the goron leader. If you are talking about in castle town after to pay 3,000 rupees. First you have to pay 1,000 to fix the bridge then 2,000 to build the store.
There are no events like this outside of the storyline in Twilight Princess- it could be an easter egg referencing the Carnival of Time from Majora's Mask.
There isn't an Outset Island on Zelda Twilight Princess only in Zelda Wind Waker and other ones.
After beating twilight princess you don't get anything.
Google "Zelda twilight princess game cube walkthrough"
He is the Master Bomb Maker in Zelda Twilight Princess
defeat ganon
The last level on Zelda twilight princess is hyrule castle where you face the final boss ganondorf.
Twilight Princess
Zelda Twilight Princess
no
No.
No there isn't