First of all, we deeply apologize for the late reply. We've been pretty busy with the Q2 release these days and I hope you will accept our sincerest apologies for this delay.
I am not a Sharepoint expert, but as far as I know, you should not need to worry about the Silverlight assemblies' security, since they are not "real" .NET assemblies. Silverlight uses its own limited version of the .NET framework, that runs as a web browser plug-in. The Silverlight assemblies are executed on the client (as opposed to the "regular" .NET assemblies, that run on the ASP.NET server) and are downloaded from the server in the form of XAP packages (that are actually renamed ZIP files). There is no GAC for Silverlight assemblies.
To run a Silverlight application in Sharepoint you just need to create a resource that contains your Silverlight application's XAP file and point the <asp:Silverlight /> control's Source
property to that resource, or if you declare the Silverlight plug-in as a <object> element, you need to set the value of the param element with name "source".
the Telerik team