Both human editors and bots should have edits go through the same API, with humans using either the default web interface, client software, or third-party integrations.
The normal workflow is to create edits (or updates, merges, deletions) on individual entities. Individual changes are bundled into an "edit group" of related edits (eg, correcting authorship info for multiple works related to a single author). When ready, the editor "submits" the edit group for review. During the review period, human editors vote and bots can perform automated checks. During this period the editor can make tweaks if necessary. After some fixed time period (one week?) with no changes and no blocking issues, the edit group would be accepted if no merge conflicts have be created by other edits to the same entities. This process balances editing labor (reviews are easy, but optional) against quality (cool-down period makes it easier to detect and prevent spam or out-of-control bots). More sophisticated roles and permissions could allow some certain humans and bots to push through edits more rapidly (eg, importing new works from a publisher API).
Bots need to be tuned to have appropriate edit group sizes (eg, daily batches, instead of millions of works in a single edit) to make human QA review and reverts manageable.
Data provenance and source references are captured in the edit metadata, instead of being encoded in the entity data model itself. In the case of importing external databases, the expectation is that special-purpose bot accounts are be used, and tag timestamps and external identifiers in the edit metadata. Human editors can leave edit messages to clarify their sources.
A style guide and discussion forum are intended to be be hosted as separate stand-alone services for editors to propose projects and debate process or scope changes. These services should have unified accounts and logins (OAuth?) for consistent account IDs across all services.