First let me remind you, the scope for the question is very vast. What I will try to do is list out pros and cons of using Drupal and provide you a general direction to start,
Firstly, yes Drupal is perfectly capable of handling sites of these type with efficiency and a large number of such sites and created using Drupal. But please do remember, Drupal is an open source CMS and dont expect to get everything ready and out of the box. Be prepared to get your hands dirty and try out a few stuffs.
But what Drupal will provide you is with an awesome API to ease your work and a set of very powerful contrib modules. in a nutshell, I think Drupal will be a great choice in your case.
Now a general direction and a few contrib modules you can start looking at:
- Workbench Moderation - this awesome module will help you to create all sorts of workflow for document creation, approval, and publishing.
Now a word for your concern regarding Drupal backend, i agree with you it is a bit too much for non technical guys but with a pro that it is functionally solid. So what i usually tend to do is redesign the forms and create a dashboard like stuff for the non admins/content editors. So with a few sets of permissions, form layout change and css you can make that really usable for non technical guys.
Hope I could provide you with details you needed.