Script writing mode questions

Hi,
I have two questions: is there any shorcut to apply a style to a part of the text? (scene heading, character, action, etc.) Each one looks associated to a letter (S, A, C…) but I can’t find how works the shorcut…
Is it planned for the future to update the style INSIDE the document when the script settings is modified? Because it can be very long to do it manually. And I can’t see any advantage to modify the parameters if it doesn’t affect the styles INSIDE the script…
Thanks