Here's one approach, but certainly there are numerous variations on a theme:
Webform - create web script to render and process the form data. You'll have to develop the html for the form. The web script function provide security as well to enforce which users can access this functionality. It may also be possible, depending on your specific needs, that you don't need a separate html form and that the forms that can be generated in the workflow module are sufficient.
Workflow - Alfresco integrates nicely with jBPM workflow engine and it is included in the standard install. You can create custom workflows that integrate with the Alfresco repository. Emails can be generated when a task is assigned to notify a user of a task. Timers can also be configured.
Setup Space (folder) - create a space and use built-in permissions functionality of Alfresco for controlling who can see/add/edit a document. The Alfresco Explorer client provides this functionality.
Excel download - not sure exactly what data you want in Excel, but Alfresco integrates with the Office suite. Depending on what you are looking for you may need to write a web script to extract data from the repository that is then imported to Excel.
And good news is that no Java coding is necessary to implement any of this. Server-side Javascript is supported and I believe so is PHP, but never looked at PHP functionality. Some customization may need Java skills, but just depends on the complexity of the problem you are trying to solve (e.g., heavy calculations or the need to support a high transaction volume could lead you to a Java implementation; custom actions or new transformation).