most times its not a piece of clothing that gets spun over top, but more or less, when loading or unloading, clothing pulled out in bunches, a simple sock can get rolled under the splash shield, and before you know it, it jams the pump....
you can adjust the water level up, keeping it just below the top vanes of the agitator....like in Joe's video above, he is about spot on for highest fill level...
as for the dryer, chances are, its needs cleaned and lubed, especially the idler pulley and that back bearing....most of the screeching will come from there...