got it to work for me.. at least i posted something using the share-dialog.. still having trouble with the feed-dialog, but thats on the facebook side..
what i meant is .. you take the key hash, that it says didnt match - and put this into fb's developerdashboard under settings into your "android" section.. quick n ugly but should work
i managed to do it this way.. i created a new keystore with
keytool -genkey -v -keystore .keystore -alias androiddebugkey
the password for the alias _must be_ 'android' (don't ask me why.. it's what i found somewhere)
and now generate a key-hash for facebook from it with
keytool -exportcert -alias androiddebugkey -keystore .keystore | openssl sha1 -binary | openssl base64
now you can setup that newly generated keyhash in fb's developer dashboard (->settings/android) again and now - at least for me- the cordovaFacebook plugin works... (on android that is.. i didn","t test it anywhere else so far)
ah.. and in order to develop with this.. you have to create a scanner-build which uses that keystore obviously and includes the cordova plugin..