Toolkit,
Sorry for the delay. For the error you're getting when viewing your App, it seems to be an SSL certificate problem on your site. If I go to the SSL version of your site directly (outside of Facebook), I get a similar error:
www.winwatermark.com/
Do you have an SSL certificate for your website? That's a requirement for the App Canvas or Page Tabs.
The App and Page Tab can have the same name. That's not a problem at all. The App Name really isn't used for much. The Page Tab name is simply a name used for helping 'find' the app if someone is searching for it. When you add an "App" to your Page Tab, you have the ability to change the name that users will see under the little box as well, so really, you shouldn't worry about the names of anything much as it can all easily be changed later...
Finally, yes, you have the right idea about the coupon code. To do what you're looking for, you should:
* Create an article saying "Like Us and get a coupon!". Fancy that up however you want

* In the JFBConnect Page Tab configuration area, set the Reveal Page ID to whatever article ID you created above. That will make JFBConnect show that article to user's who haven't Like'd your Page yet.
* Set the Page Tab URL and Secure Page Tab URLs to the URL on your site that user's should go to *after* Likeing your Page.. in other words, an article page with the actual coupon on it. JFBConnect defaults these URLs to your home page. You'll need to update them to some other 'interior' page on your site.
Hope that explains, but as always, if you have other questions, just let me know!
Alex