Hello Mary,Ok,I'll try to explain the best I can.
Any machine that has a speed reducer on it will always turn harder because your turning the motor 5x faster because of the speed reducer.The way to run it is when you get to the end slow down & learn to leave your foot off the pedal when the needle starts to go up so the needle will be @ the top so you can pull out your leather.
These new style of motors have an electronic not mechanical brake,there is no adjustment on them.
The stop when you take your foot off the pedal.
#2)The plug @ the back of the motor is for the light.
#3)Are you sure the thread is around the second tension on the side 1&1/2 times?
P.S.you don't need to stop to put it in reverse(if you don't want to),you can do it when you see the needle going in the leather @ the last stitch(rumnning slowly) & then push the stitch length lever up.
I'll give you a call today & we can go over this with you today.
Bob