Is this line in conf ->
_ # name of miner and its private key (e.g. ["account","WIF PRIVATE KEY"] )
going to contain same private key as in this line of conf? ->
_ # WIF PRIVATE KEY to be used by one or more witnesses or miners
Or is it even needed in the latter one?
Edit: put underscores for # not to activate :P
It is not required for the usual setup, but you can set it if you wish. If you are setting only a witness without a miner, then you will need it.
You should not set it for sure if you have multiple miners configured that use different private keys.