Formatting all paragraphs based on pre defined styles

[afif]

I want to format my document based on styles I defined earlier. (I attach the structure of my document).

In the outline view, I already made main title and heading 1 as level 1 and heading 2 as level 2.
Heading 1 style will apply to level 1 and heading 2 style to level 2.. I modify those two styles (font color, size).
I already defined styles as below:
-reg_paragraph for regular paragraph.
-list_alphabet for alphabet list.
-list_bullet for bulleted list.
-list_number for numbered list

What I've been thinking is that I will loop through all paragraphs. If a level1 is found, then apply heading 1 style, a regular paragraph is found, then apply reg_paragraph, if an alphabet list found, then apply list_alphabet and so on.
My questions are:


1. How can I do that ? Is there a better solution ? I can also select all bulleted numbers and apply the formatting all at once and doing this for all other components (numbered list, alphabet list, etc).
2. There are also cover pages for each chapter. I don't want these cover pages being included in the formatting. Do I need to make sections for each cover page and skip the formatting when the chapter cover page section is encountered ?
3. I do the collaboration with other author. He just makes his writing in another document and paste it into the collaboration document with different formatting and styles. Sometimes I see that the formatting for the section he writes is a bit messy when I apply the formatting. How can I avoid that ?
Thanks