Hi Hagar
I never attend an airshow hoping to see the best performances. As you say, too many restrictions ::). I always have aimed for practice sessions.
I can think of at least a dozen (frightening ;) ) occasions when I have seen an exciting performance only for the pilot to be banned from flying at the airshow 'proper'. In two instances that I can think of, the aircraft were overstressed and was retired shortly thereafter.
BTW, I still can't imagine looping a Walrus......

( not that I doubt what you say, I just can't imagine it!!!!!)
Cheers Paul