The npapi-sdk-0.27.1 release changes the API in a destructive manner, breaking random applications. Please check whether your ebuild is compatible with >0.27 (and close the bug if so), or change the dependency to: <net-misc/npapi-sdk-0.27.1
As the nsplugin itself is not working at all I am not entirely sure how to test it ;-) But please be my guest and try to compile it.
Compile libreoffice? You crazy?
(In reply to Michał Górny from comment #2) > Compile libreoffice? You crazy? LOL. Back to you. :)