First of all CMS and Hosting sites works via Remote API so everything you can do in interface can be implemented via Remote API. The only problem is to understand exactly what do you need.
We can't split 1000 drivers from same resource to grant access to different users, so if you need separate drivers lists for users - you have to create drivers in different resources and grant each user access to needed.
Logic here is pretty straightforward
- login with master account with token/login
- create user using core/create_user or find existing using core/search_items - in response you'll get userId
- create resource for user (creatorId = userId) using core/create_resource - in response you'll get resourceId
- Optionally - you can convert new resource into account account/create_account
- create driver in new resource (itemId = resourceId) with resource/update_driver
In first message of topic you are sending itemId=userId instead of itemId=resourceId for resource/update_driver
Please give me to know is something still unclear