You might have mounted the wires without enough slack so when you make a turn they pull apart. I don’t think cutting of the connector was ideal nor the culprit to the problem. I have had no issues with the Pathfinders I got. Did the high beams and the low beams with just removing side pockets. Which LED lights did you get? Don’t understand when you say you put them to the globe.

I am am not sure why you blame the bike. The fender extender is known for issues plus I never seen another bike come out of the factory from any manufacturer with a fender that follows that wrap around and catching air from the front with no where to go forcing a break.

Never had any problems with the seat bolts. I didn’t like the hex head so I replaced them with matching shaft length socket head bolts and washers . Put grease on the threads to prevent any issues. Ace Hardware had them. Just bring in your bolts to match up thread and length.