Hi Simon,
congrats, the boat looks great. Trapezing with spinnaker on your first time out is certainly showing your ability, I am sure you will be feeling comfortable with the boat very soon.
A word of advice if I may. In the nose dive photo's, it looked a bit like your mainsail may have been eased a bit too much by either sheet or traveller. This is what tends to cause the nosedive, as you bear away with the increase in speed on trapeze, the head of the mainsail starts to attach flow or slightly oversheet, which drives the bows down. If conditions are at risk of overpowering, I find it best to sheet the main in firm so it completly stalls, so the deeper you drive away under spinnaker the less the main has effect. It is slower between gusts than having the main set correctly, but if you are on trap it is the only way I have found to survive most bear aways, not all of them though <img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" />. Footstrap on the back corner is a must as you know.
Look forward to sailing against you one day. <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />