Hi Tom, I have owned Waves since 1999 (as many as three at a time but now just one) and have always had the hooks. You gave the answer in your question - just keep some tension on the sail as you lower the main. You simply teach yourself a new habit. Write a reminder to yourself on the luff of the main if that's what it takes to remember (I'm not kidding) - very easy to do and very inexpensive! Before long you remember to do it automatically - just like breathing!
More simple advice for your other problem - move back! If the bows go under the water, move your weight back! That easy. Do not mess around with diving planes or other add-on crap. It messes up the boat, costs alot, is a bunch of trouble, and delays the learning process.
Now go sail some more and practice these easy solutions! ;-)
Mike
A large part of the Wave's attraction comes from its simplicity; do not fight it! Adapt to it, do not adapt it to you. You will come to appreciate its attractiveness when you are more receptive to it.