SSRS and SharePoint: Native and Integrated Mode – The future?-Collection of common programming errors

When the articles mention the Report Server is talking about the Web Part of reporting (well is the web part and other services part), a good example of it is the ilustration of the Three-Computer Deployment in the article http://technet.microsoft.com/en-us/library/bb510781.aspx, if you look at it sharepoint and reporting databases are in the box at the right without anything else.So for your concern in the cluster , you can install the databases of sharepoint, reporting and any other applicattion in your cluster, and in different box install the sharepoint and reporting or as the article shows a box for sharepoint other for reporting and the cluster for the database.

About the feature differences , personally I don’t have info about it.