I noticed that our extruder that did not have the swivel guide tube would sometimes disconnect itself from what seemed like the filament guide tube hitting the lid of the printer. So we took the lid off and it solved the problem. our new extruders have the swivel guide and I don't get disconnect errors anymore. You can also try the clip Elbruju mentioned although I feel like that caused more of a problem than it fixed.
Not sure about your other problems.