Can confd-load be used to load into candidate data store

Can the confd_load application be used to load into the candidate data store?
Can it be done without committing?
i.e. Load a set of changes from a file, then an external system commit the changes.

No, if the transaction has been opened towards candidate, confd_load always commits candidate to running. But not much needs to be changed to modify this behavior; the tool source code is distributed with ConfD, so feel free to modify it according to your needs.