No, there is no out-of-the-box solution, you would need to hack the core.
Currently, the best you can do to make it clearer for your client is probably using custom icons for pages Custom icons in the Panel although I don’t know if this has made it into the core yet (don’t think it has).
As regards different snippets in different orders, you could use a structure field and have the client select the widgets for a particular page via this field which would also make it possible to sort the entries.