Where abouts in NZ is that? LOVE the massive tripple bar you have as first pic!!!
Overall the pictures look great - the horse is a very talented and scopey jumper, you're position looks very secure and you certainly aren't hindering the horses jump in any way at all. I agree that more of an automatic release could be used, so your hands will go more towards the horses mouth rather than up the neck, therefore keeping the straight line from elbow to bit.
The only thing I can notice is landing from that big hedge, just watch you don't get left behind and end up sitting on the horses back. I know it's hard to stay off their backs when they have a jump like this - my guy is the same, he really throws his back end away on landing like your horse is and you feel like you're going to get thrown forwards unless you really sit back. Sometimes it can unblance the horse and make their back end drop down too soon on landing - can cause a back rail of an oxer to go in show jumping. Bit hard to tell from that angle whether or not your seat is actually touching the saddle, you just look a little behind the movement - but you certainly aren't getting the horses way whichh is the main point.
What height do you compete him? He would easily do at least novice or 2* course going by those photos!