1. About the css code, your css code above is wrong. You will need to put something like this below :
2.a Can you provide me url of the page that contain landing slider that you refer above, i will check it out.
7. You may need to check this article https://codex.wordpress.org/Creating_a_Static_Front_Page about setup front page (homepage).
8. About text block, at the moment we don’t provide that option. But you maybe you can change the color of the text using color option on toolbar.
9. You will need to add custom css to achieve that.