1) All the strings for the SCLogin module are in our language files:
/language/en_GB/en_gb.mod_sclogin.ini
You can change it there or use the Language Manager -> Overrides feature of Joomla to make a permanent change that won't be overridden when you upgrade.
2) Please see our Theming guide, which will show you what files to edit to change the CSS or layout to your taste:
www.sourcecoast.com/sclogin/documentation/themes
3) In the User Menu that you created in the Joomla Menu Manager, create a new menu item as follows:
* Type: External Link
* Title: Logout (or whatever you want)
* External URL: sclogout
When you set the external URL to sclogout, the SCLogin module will automatically replace that with a real logout link, just like in the dropdown menu of this site.
I hope that helps, but if you have any questions, just let me know!
Thanks,
Alex