See Where can Building Blocks be stored?
See also: Build & Deploy Custom Building Block Galleries by Greg Maxey

You cannot remove BBs on other people's machines and do not need to do so, even on your own. Custom Galleries should handle that for you. On your own machine, you can use the Building Blocks Organizer or can use Greg Maxey's Organizer Utiility. Building Blocks & AutoText by Greg Maxey.


Also consider using Buiilding Block Gallery Content Controls.


Mapped Content Controls, other that the built-in Document Property Content Controls cannot be stored in building blocks.