Nesting is top tension too loose by a lot. This can also be from the thread not being seated fully into the tension disks or the presser foot being left up when sewing.
The most common reason for skipped stitches is the needle is in the wrong way. On the machine you showed here, it's likely flat to the back.
Needles striking the plate are either the wrong needles, bent needles or most commonly pulling or pushing fabric which causes the needle to deflect.