
It sounds like a fun class you go to, what a great idea.
Walk backwards is quite easy. Dog is standing, you stand infront with a treat held to his nose, step towards him and say 'walk back' even if he only puts one foot back at first, reward him. Just build it up gradually, he will soon get the idea.
Dog Bowing. I have taught this with a clicker, firstly show what you want with dog standing infront of you, treat in hand, quickly place hand and treat on floor (sort of level with nose), he should bow if you are quick enough and not go fully down. Click and treat. You have to be quick with your movements on this one, just keep building it up and eventually stand still and wait for him to do it, he will work it out by himself, click and treat as soon as he does. I usually say 'good bow' when he has.
Don't know about no.2, I would be interested if someone does. The backward one is the easiest to teach, but you could show off with the other two :D
Sandra