Provide an "asset library" to store customized blocks or other items, e.g., buttons, that can be reused on other web pages (so that the assets don't have to be recreated each time). The library could have subsections, e.g., "Saved buttons", etc.

The asset library could include a section for outside assets ("Uploaded files") such as PDF docs, images, etc. They would have associated URLs for linking from a site page.