the tab "Purge items" should only be visible if the feed got items

I think I won't immediately add the capability of hiding Purge items when the feed doesn't have items at all. It's not a problem is the module enables you to delete 0 feed items. It doesn't hurt anybody.

I agree it could be more comfortable if the user receives response of what happened, I'l transform it to a feature request. At the feedapi_invoke_feedapi('purge') call the module should provide more verbose response.

Thanks for telling me that this behaviour can be confusing for the users.

The real problem is that the user doesn't receive a question about the deleting.

In the 5.x-1.x-dev (-r DRUPAL-5 in the CVS), the behavior is changed. The user is asked for confirmation before purging all the news items.

the tab "Purge items" should only be visible if the feed got items

Can you explain me why is it meaningless to apply the "Purge items" command to a feed without items? It simply means that 0 item will be deleted. But in my opinion, it's not a bug.
Can you explain me what will go wrong if you can click on that menu and FeedAPI inform you that 0 item was deleted ? This is the behavior of 1.x-dev version.

The problem is that i have too may tabs.

It sounds me like a feature request. It's not a bug that you have too many tabs, i assume. Do you think it's a good idea to have a setting option to turn off the FeedAPI tabs?

This could be a potentially expensive query. Not sure whether this would be a good idea at all. Closing.