There isn’t a direct way to control the aesop add component button through CMB2 but you can hide it with css is the best suggestion I have there. I’m not sure the filters that we have for that button would work in that application.
Can you clarify a bit more on #2? The components are shortcodes so if you’re saving field data in a wysiwyg field just echo out the var like so echo do_shortcode($var). That is if I understood your query correctly.