Currently, the only thing you can change about the buttons, is their SIZE and POSITIONING (using any of the 4 layout templates). A future version may include more buttons, and/or the option to upload your own button graphics or point to your own uploaded images.
From my own experience, the four options you have are the most common ones that people use. If, however, there is another layout that you think could be useful, please let me know and I might add it in a future update.
As with every plugin, it's possible that things don't work. The most common reason for this is that the plugin has a conflict with another plugin you're using. It's impossible to tell what could be wrong exactly, but if you post a support request in the plugin's support forum on WordPress.org, I'd be happy to give it a look and try to help out. Please include as much information as possible, including a link to your site where the problem can be seen.
For any other issues, please use the WordPress.org forum.