I would second Dom’s suggestion to focus on import/export first. I mean professional translators use offline and online tools that are far better than anything we could implement within the admin, e.g. those systems have translation memories and do suggestions based on similar translated content.
I don’t say that we don’t need it. It would be good to have what you mentioned. Left text always readonly the original content, right text area the translated content - language selectable via dropdown. Or do you mean the frontend UI?
For the export I have the following in mind:
- select object types to export (select/deselect all option would be good)
- select languages to export
- produces XLIFF file format
- it would be cool to have granular permissions, also on content, e.g. export of only a specific language or object type allowed
Import gets more tricky. We would need to have some kind of preview and approval workflow. Maybe the draft status can be used for this one. But there are nasty exceptions, e.g. while importing there is already a draft version on a specific translation object.
Oh… and if we are talking about drafts - even though this is a different topic - but it kind of would belong to this workflow as well.
We would need a single UI to bulk preview/publish drafts (from different object types and all at once).
Think of a grid that you can filter for all objects that have draft changes, quickly examine all those drafts and then publish all at once.