Control WordPress Formatting on Section basis.

Hi,

I want HTML (includes javascript) contents into post. But wordpress formats and changes few tags and strips the javascript tag(though i have disabled the option of using Rich Text Editor). I want to override wordpress formatting on per post basis.

With this scenario, bellow are my question:

1)Is this wpautop function is a global or specific that takes care of formatting ?
2)How can i avoid wordpress formatting only for blog post?
3)Is there any functions that takes care of blog post section only?
4)What does the function wptexturize does?