Most schools in the UK teach 2 stages for a normal landing and full for short field in a Warrior/Cherokee. For the cessnas with 40 degree flap this was generally used again only for short field , 30 being the norm.
As I recall the last stage of flap does not change the pitch so the picture does not improve by applying stage 3. Stage 3 just adds drag requiring more power to remain stable. Unless the rwy is short I guess most people have compromised on the 2 stage approach. Going around with full flap makes climbing hard or impossible so I guess thats another reason to use 2 stages.
It probably all goes back to the first chaps to write the checklists when the cherries first arrived and its been done like that ever since.
Having said all of the that the military stuff (bulldog, firefly, Chippy) only have two settings for the simple Takeoff (10deg?) and Landing (More degrees).
As for gusty conditions I used to go for no flap and loads of speed (perhaps a bit too bullish)