I pretty much agree with what you say here. Only caveat for me is that I don't think 20 dives is too few to be taking Rescue. Of course it varies per individual. I did mine after dive # 26 and did OK--Great on some skills, not so good on others. But the purpose is to actually do toe skills in the presence of an instructor as well as to gain the book knowledge, of which there is a lot. After I completed mine, I mentioned a couple of skills to my OW buddy, just in case I ever needed him to rescue me. It may not be ideal to take Rescue with, like, less than 100 dives under your belt, but, you do get the knowledge. And it need not be done in 6 foot waves.