The G3D performance impact is fairly huge in this game unfortunately. Will be a bit better with next vorpX, but even then you might want to switch to Z3D at high resolutions.
I’m not really sure if I understand the mouse problem. You don’t have to play with mouse and keyboard. For games like this, which can’t handle simultaneous mouse and gamepad input, vorpX comes with a reasonably sophistcated gamepad to mouse/kb mapper that is freely configurable. Should be enabled per default. If you disabled it accidentally, try to reset the profile to default in the config app.
There always is a chance that the scanner may fail unfortunataly. Hence the message in that regard that is shown during each scan. If you happen to use any other anitvirus program than Windows Defender, get rid of that. Some more invasive ones may prevent the scanner from working.