One thing i did notice that no one has mentioned,the first pic in your post #5 your stuffing tube is not attached to your strut. The loose stuffing tube can also cause flex breakages because the tube and flex can wobble around in that area. I would recommend trying to get the stuffing tube to fit into strut blade. Also grease flex before installing into stuffing tube and keep greased properly,but don't put grease on the tip of flex which goes inside collet,that can cause the flex shaft to slip. If you hear a "howling" type noise after a few minutes of running check your flex because the grease may have come off and the flex will be spinning inside a dry stuffing tube which will also be a disaster.
Happy Boating!
