zpool destory [name] will do just that. It will destroy your pool. If there is no data in the pool, then you can do that. If you want to 'get rid' of the pool preserving any data, you want the Export button. This closes the pool down and puts it in a state where it can be relocated. Like unmounting a volume. You can also do this from the terminal:
Unfortunately that error was introduced by a user with a particular zfs setup. His pr was not well tested neither by him or the dev team. hope we can fix that in the next release as well as other issues. You can read more in github.