Knobbygb
You have checked flap integrity and operation as part of preflights, so assemetric deployment is unlikely.
The flaps were mechanically operated not electrically operated, it was a low wing aircraft not a high wing aircraft
The big thing I remember in the Cherokee was to make sure you haul on two stages, not three, but it had a big handle and definate clicks as I remember, and it was fixed u/c so no confusion there.
However as I previously said it was a long time ago and I personally would want to go through the manouvre with someone current on the procedure before trying it again.
My experience of rough and unlicenced strips is such that I give them a miss.