There is limited capability in CRM to audit customisations. There are the Import and Publish messages, which don't give you the level of detail you probably need.
There are no plugins that fire on the create of an entity or attribute.
However, your requirement in the last paragraph relates to auditing changes to the form layout, rather than changes to the entity or attribute. For form changes, you can register a plugin on the Update of the SystemForm and UserForm entities, which may give
you what you want
Microsoft CRM MVP - http://mscrmuk.blogspot.com/ http://www.excitation.co.uk