Correct metabase is readonly. And i think thats a good thing. For BI tools such as these you have many types of users and generally want it to be strictly readonly.
Right now, SkyAlt can't write to the remote databases and in the future, it will be able to write only data, not change a structure(create/remove columns, etc.).
This will lead to the option to build internal tools. Adding dashboards and writing to remote databases should be easy to program, but right now I focus on stability, usability and documentation for current features.