1 - (optional and often overlooked) one pointer to your sitemap (or to a single sitemap index if you want to indicate several sitemaps files).
The sitemap is just suggestions to help the spiders to spider your site and to speed their discovery of it. They bring NO guarantee that the pages you indicate will be eventually indexed, not even that they will be spidered in the next hours. And of course the sitemap is not a restricted list of what should indexed,nor that nothing else should.
So, what's wrong with this pointer in robots.txt not being used in the next 24h?
Maybe my robots.txt can just say look at sitemap.xml and nothing else
I only want 8 pages in google and the rest of the pages on the website, I would like hidden
deny the rest