Custom importers permissions
It would be very interesting to be able to assign execution permissions to custom importers. For example I would like a user to be able to access the functionality of the extension but only to be able to run the relationship importer that I have customized.
At the moment "import contacts" core permission it's required. Surely it would be interesting to add a couple of extension permissions. One to access the page of the extension civicrm/advimport and a second to enable execution of the default importers provided in the extension. Then every custom importer defined in other extensions could define their own behaviour.