How can I change the padding and line-height of the menu items in the submenu drop down?

I have a few questions regarding the code needed to style menu items in the top menu and the submenu drop downs, of which some of them are mega menus and others are normal):

1) How can I change the padding and line-height of the submenu items?

2) How do I create a custom class for submenu items, so that I can enter the class in the custom class field on specific menu items.

3) How do I create the normal, hover and current page states for the top menu items?

i.e. normal: #333, hover: #CC0000, current: #CC0000

URL: http://tinyurl.com/lxtd849