What do I open the ROM with?

I use Wabbitemu https://wabbit.codeplex.com/

You can map custom controls to keyboard in the Wabbitemu options.

Thank you :)

Is there a way to change what key you wanna use for STAT PLOT?

Yeah, you can remap keys in Wabbitemu.

In the menu bar, click Calculator > Options > 'Keys' tab > select 'Emulator' in the 'Category' drop down. You can select a calculator button and assign it a keyboard hotkey.