1. Is there a way to find out what all documents are using a property within my aspect? How do I search for this. The only examples I see are searching for values within fields. I only want to list documents that have values in a particular property within my aspect.
2. Is there a way to delete an aspect? If documents are referring the aspect do I need to remove the aspect from those documents before deleting an aspect?
3. Can I delete a property alone within an aspect?
1. You can type in Share Search something like ASPECT:"qshare:shared" (for example), where the text between " is the name of your custom aspect. This should show all objects within this aspect. But if you only want to list documents that have values in a particular property within my aspect, you can search by this property @myroperty:"apple"
2. If you refer to that you want to delete / deactivate a content model with an aspect, you should clean your documents, with these aspects. This clean may be done directly in Alfresco Share or via script in JS Console. Then you can deactivate your model and delete it.
3. If you are saying about updating a content model with an aspect, deleting a property of the older defined... you can do, once the old model is deleted / deactivated.