Can anyone help me with a ROM?

I've got a physical cartridge of this ROM hack online so certain things may not be accessible like it is on an emulator.

The game itself is Pokemon: My A** Edition. My problem is, I can't get to the sevii islands.

I'm aware on an emulator, you can use a walk through walls hack to use a walk through the rocks west of Cinibar Island but like I said, I'm on a physical cartridge so I can't do that. Is there a way I can get to the sevii islands now?

Another Quick query, anyone know what the ??????? Item does? I bought one from the mart and just have no idea what it is-

I'd really appreciate if someone could help out!