excellent lesson! My only comment would be to mention the issue of vulnerability. For example I opened four spades with QJT as top of an 8 card suit while vulnerable. I was doubled and went down two giving the opposition 500 points. I should have only opened three giving that I was vulnerable and missing the top two honors.
Yes vulnerability does play a part. It pays to be a little more cautious when vulnerable. Conversely if you are non-vul and they are vul - pre-empt as hard and as high as you dare!
2C as an opening bid has a special strong meaning - lesson 10. So yes, you don't get the chance with a six card suit to open 2C preemptively. Of course you can still open 3C with a 7 card suit and 4C with an 8 card suit. Good luck with your bridge Simon.
Yes you can respond with 3C .but when partner remains staymen u can bid 2 heart 2 spade but u cant bid 2 diamond...2 diamonds is a negative bid it means you have nothing just nothing to show ...if you have good diamonds suit you have to bid 3 diamonds.
