The person who agreed to help me is stuck as well. If someone else is willing to help I have now played through the 8 first dungeons and I can provide screenshots and savestates.
November 05, 2016, 10:31:18 am - (Auto Merged - Double Posts are not allowed before 7 days.)
Now I noticed another thing:
If I open the rom with the LALE editor (A Link's Awakening DX editor) it displays AAAAAAA etc. where the text about the Thunder drum should be.
Additionally a box saying "Question yes or no" is ticked. However, if I open the rom with a HEX editor the correct text is displayed in ASCII.
I've tried to change the text with LALE (both with and without the checkbox ticked) but then the room with the Thunder drum goes bananas (sprites are flying everywhere and I can't do anything). Also, the changed text appears in another place in the edited rom (a bit further down) if I open it in a HEX editor.
Later when I looked a bit more in LALE it seems like the correct text is at the end of something called pointer 106 (instead of 107 where it is supposed to be). I've read a few rom hacking documents and tried to look around with a HEX editor and pointer calculator, but I haven't been able to figure this out