Alternatively, instead of bombs you can probably use the Megaton Hammer recoil to initiate a super slide.
There is also an easier way to enter the shop but require hover boots using a megasidehop
In Darunia's room, there are two lit torches, and two pots which drop Deku Sticks. Use the flame to light the torches in the bottom floor and up to the Lost Woods entrance. Touch the flame to one of the bombs to light it.
There are 2 ways to enter Darunia's room without talking to the goron
This method is hard and shouldn't be used
A fairly easy way to clip inside of Darunia's Room is a ground clip, the angle is pretty lenient.