Regarding the breaking of needles while hemming jeans, etc. It is important to keep the pressure foot level. In my tools box, there is a item referred to as a "hump jumer". Each end has a different thickness. When approaching the seam and the toes of the pressure foot at leaning upward, slip ther jumper under the rear of the foot thus leveling the foot; carefully take a few stitches; then move the jumper to the front of the toes when they drop downward and carefully stitch past the seam. If you don't have a jumper, use a ruler.
Hope this helps to avoid those broken needles. Suzanne