Yes, several SharePoint features will not function properly until your site’s URL has been added to your "trusted sites" in Internet Explorer.
Unfortunately, Business Intelligence features (such as PerformancePoint) are not currently available in a shared environment. However, these features are included in the SharePoint Server 2013 Enterprise edition and are supported in a Dedicated SharePoint environment.
Office Web Applications (OWA) functionality is not available. This functionality was removed to comply with Microsoft's licensing terms.
We are exploring possible options to be able to add OWA back to this environment but there is no time table for a resolution. It should be noted that OWA is still available for other hosted SharePoint solutions at Rackspace. If you agree with us in thinking this is an anti-competitive move on Microsoft's part, we encourage you to speak to your Microsoft account representatives and let them know.