Hopefully your film is not in as bad condition as your scans.
The black line at bottom right is indeed a hair in the gate.
I would honestly take the film back to where you had it scanned and ask them to re-do the scans.
Also if you have a light leak I would have your camera serviced and repaired, its only ever the great photograph that you always wanted to take that will have the light leak.
Simon ILFORD Photo / HARMAN technology Limited :