You've discovered the obvious — your users vary greatly in what they need and can use in your CMS. Many use the CMS but only for what they absolutely must and no more. Some are adventurous and quickly land in hot water. A few take to it aggressively. All make demands on IT for support. Everyone is complaining. ROI is elusive. Typical situation.
What do you do?
Whether you've got a deployment or redesign underway or are looking to implement a CMS, your vision should include a flexible model which provides the right capabilities for each of several types of users and then evolves over time. Don't overwhelm today nor underestimate the demands six months out.
Our Workspace Model is a methodology to right size any CMS's capabilities and guide its evolution with a staged, iterative approach which controls risk and costs.