I believe PR1.2 is going to let you choose to disable the volume buttons being zoom in the web browser as it annoys so many people. So if you do use them, it would be nice for it to be a toggle option in the menu as not everyone is happy about losing volume control.

Is it possible to use Fn + Tap to be left mouse button to partially fix this problem?

My own current major issues:
Need at least F1-F4 mapping for Pinball Dreams table selection. This could in this case comfortably be something convoluted like Fn+Ctrl+1 for F1, etc. RSHIFT or RCTL also may need mapping for right flipper control, I can't remember if any other buttons are assigned for right flipper that already work. Mapping to N should suffice (assuming M is going to become left joystick button as suggested above with SPACE being right joystick button).

There also needs to be a way to disable the keyboard remapping for entering your name in hiscore tables etc. Possibly an on screen toggle button in the blank space on the left/right, you could still use the middle part of the screen for controlling the mouse. Of course a plain old option in the menu would do for the time being.

Minor Gripes:
On screen LEDs are taking up space. Would be useful if you could move those to the left or right side of the screen where there is empty space.

Sound is Mono.
Is Stereo sound a major performance hit as I rather loved how the Amiga had full Stereo Separation with some instruments only on left, some only on right. (its even cooler in WinUAE when you have it in surround mode with each channel in a different corner of the room)