Conditionally unpublish nodes for feeds
You seem to be using a version of feeds that is fairly recent (perhaps version 7.x-2.0-beta2). Having said that, the process function of the FeedsProcessor class is fairly inflexible when it comes to modifying the list of imported nodes that it wants to clean out of Drupal, in that it does not provide a hook to modify that list.

Having said that, your best bet is probably to extend the FeedsNodeProcessor class and only override the initEntitiesToBeRemoved function to then exclude "potentially unpublished" node ids from $state-&gt;removeList. You'll need to determine how all of the nodes from $state-&gt;removeList were created.

How you determine a manually created node from a feeds imported node is up to you but I would recommend querying the feeds_item table. If a node's nid is not found in that table then it's safe to assume that the node was manually created.