Thanks for all those ideas friends! It seems most of you took the "suggestions welcome" option rather than answering the questions directly (you would have been marked down if this was an essay question!) but I get the impression that I do need to actively change a few things rather than continue on in the same way and hope that practice will cause things to come good eventually. Thank you Jupiter and Formula Nova for answering question 3.
Roar, yes, that's what I am aiming for!
S'board crazy - I think I may not have any more good planing gybe practice sessions this season. Monday was a bonus, and Formula Nova, it was at Safety Bay, 16 - 18 knots, really flat. There was just enough water to gybe over the bar but a few fin scrapes were making me nervous.
Going in with speed - I guess I tend to do speed sailing on the really windy days and keep my gybe practice for the more ordinary or marginal days, so on my practice days I am never going in really fast. Probably around 20 knots at best. I have to admit that if I am going really fast I get too scared to gybe

. Most of my injuries and board injuries have come from overpowered gybe attempts, and often when it is really windy I am fatigued or arm weary and decide it would be risky to gybe and safer to just stop and catch my breath.
Patrick & Decrepit - I do tend to do 180 degree gybes rather than 90 degree gybes, so I don't lose too much ground downwind. As an exercise I shall concentrate on the 90 degree gybe for a bit, and work on keeping the board heading down wind after the rig flip, then tighten it up once I have that happening.
I don't think I need to concentrate on the carve - carving around too far is my problem if anything. My footwork isn't a problem. That is so automatic I don't have to think about it at all. It would take a great effort not to change my feet.
So things to work on next time there is some consistent wind - practice gybing in strong wind before I get tired, to really get some speed up.
On the less windy days go for the 90 degree gybe with a good broad reach to start with
Work on keeping the board pointing downwind during/after the flip
Don't hook in until I am planing again on the new tack.
I suspect I need to pull the sail forward more when I grab the new side of the boom, to keep my weight forward and on the front foot. Weightlin gthe back foot pushes the back of the board around too far.
More ideas welcome...