Upfront Fixer header slider

I am not sure the best size for slider so I created 1200x1000 and position the image on black background where it looks best on PC.

Now I find the slides screw up on tablet and mobile.

My questions:

1. Any suggestion on image positioning on each slide?

2. How to disable slider if the sliders are not resizing themselves?

[image pos="0"] [image pos="1"]