You only need one license, no matter how many servers you have. We track active clients, not licenses.
Keep in mind that GG is a very new product. If you force remove the gluu-gateway package, and the oxd-server package, and tehn rm -rf the folders, it should get everything. One of the reasons I prefer the Gluu Server chroot installation is because it's easier to remove.
Also just a heads up, we're pushing a fix to GG this week around proper handling of subfolders.
If you want to see a demo of the Gluu Server, you should look at [gg-demo](https://github.com/GluuFederation/gluu-gateway/tree/master/gg-demo). I prepared some slides for a talk at Identiverse where are [here](https://goo.gl/19Hz8M)
Post more specific info here when you get further.