Hi,
As a general practise you should create a dedicated replication user (say replication-user) with administrator privileges and expose permission with respect to only those areas which are relevant for content authors to replicate / activate to publish instance(s). To answer your question
A. To add content to the publish instance
Answer : replication-user, assuming that you don’t intend to add anything directly logging into publish instance.
B. To load content form the current instance
Answer : In publish instance(s) everyone user has default read only rights for this purpose.
C. To apply user rights
Answer : this has to be any user with administrator privileges – i.e. added in Administrator user group.
Hope this helps !!
Regards
Sandeep
