Content Tabs (cTabs) allows you to post content into separate tabs on a page using shortcodes. [shortcodes]
WordPress wants you to place all of your shortcodes on a line by themselves. I try to keep the line above and below my shortcode empty when I use them. If there is content on the line above, below, or beside the [shortcode] it will add a lot of
's to the top of the tabs.
Currently no. I plan to make that option available soon.
Yes. cTabs is very customizable directly from the admin options menu. Modify the CSS however you want. Option to reset to default is available.