Thanks Robert. Your answers are good ones. I appreciate the response too.
I don’t really have a problem personally with the licensing, as long as that is the cost I am paying for the work put into the platform and the overall service and those costs are also not taken into account in the infrastructure. For instance, you might need the licenses, simply in order to control access. Your licenses are reasonably priced too, thus not a KO criteria IMHO. And then again, if you have a user access system, but don’t really care about how many users are on the system or rather you know the number of added users won’t be excessive in any damaging way, then the licensing might not be necessary and the costs for the platform’s development and maintenance can be spread across the infrastructure services.
Galera Cluster isn’t too bad. I consider MySql Cluster the better solution currently though. What makes it unattractive is Oracle luking behind it. LOL!
What intrigues me is why don’t you support MongoDB? The PHP driver is pretty good and the new driver PHongo is going to be pretty cool too, especially if their vision of PHP developer driven extensions comes together well. I hope it does. But certainly, if your goal is to provide Node.js support later on, then offering MongoDB support with it is a no-brainer. 
Scott