I suggest that you keen young bunnies get yourselves along to a British Aerobatic Association (BAeA)competition this summer and see what fun you can have.
http://www.aerobatics.org.uk/sites/events-info.htm
The BAeA have a list of buddies on their site, too and if you were to contact one before you attended they'd show you around, introduce you to the players and generally explain how things work.
MadGirl - there are several different flavours of humpties; you have described a pull push pull humpty but you can have pull pull pull, pull push push, push pull push, etc, etc!
The secret is not to get too slow at the top - 85/90mph is about right in the Pitts, any slower and it is liable to start torqueing off the top and you'd end up downhill on the wrong heading!
Stik