Moving the bottom edge of the crop tool in (Camera Raw window) is suddenly too close to lifting the filmbar

Same here. I finally realized that you now have to hover over/under or left/right of the grab points -- within the image -- and you’ll see an arrow appear that allows you to crop without affecting the ACR layout.

Have you tried placing the filmstrip at the side i.e. vertical mode instead? May not suit you but should alleviate the problem.