Potlatch2 customization - how avoid new feature creation/displacement

Hi,
How can i block the creation of new features (node, way, relation) and feature displacement with a custom Potlatch2 ?

The purpose it to deploy an editor only for internationalization of names in the breton language, for users who have no idea of the OSM model. User select a feature, add or correct the name:br tag, and save it.

Any idea ?

Bruno

Worth asking on the potlatch-dev mailing list - I believe Eric Wolf at USGS has done a bunch of work on this.