Ad 1. You can add it by right-clicking on the Styles folder and choose 'add existing item'. The CSS is then added to the ePub.
Specify the epub, but putting the following line between the <head>-tags:
Code:
<link href="../Styles/stylesheet.css" rel="stylesheet" type="text/css" />
You need to add the class= by hand of course. However, you can use search and replace with some RegEx. That might be useful to save time.