Missing features in a SharePoint

 Run the Test-spcontentDatabase command against the content DB to get the list

use this SharePoint Feature Administration and Clean Up Tool to identify and remove them

You can uninstall it using stsadm as for SharePoint 2010

stsadm -o uninstallfeature -name {MyFeatureName}

where {MyFeatureName} is the name of the folder the feature sits in the FEATURES folder in the SharePoint hive.

stsadm -o uninstallfeature -id {GUID}