As far as parking goes, I don't give it much thought.
I Never had a bike roll away, so I guess I'm parking correctly.
As far as stopping Left foot down.
As far as shutting the bike off. I was always taught to use the kill switch, so I always have. I pocket the key.
I watched a guy back flip an interstate in the middle of a crowded parking lot at bike night at a local wing joint. He pulled up and started walking the bike backward into a parking spot that was slightly uphill, he had the bike in gear, clutch pulled in. He started to fall to the left and in his effort to hold the bike up he twisted the grip to full throttle. He couldn't hold the bike and when he let go of the clutch the bike SHOT forward and wheelied over backward while hitting the curb on the island across from him. It actually flipped in mid air. The fact that it missed all the people and all the bikes was amazing. The bike was totaled. The guy standing next to me said "not again!" He said the guy had just gotten the Valk because he wrecked another bike the same way. WTH??
Friend on a Goldwing did the samer thing BUT he didn't let the clutch out. Blew the engine.
I keep the bike in gear so IF I start to tip over I can let the clutch out, move forwad and straighten up.
Sounds like the guy on the I/S needs more practice on 2 wheels. Maybe with some training wheels ?