No I do not think you have a problem with your setup. You are correct that if you want a RadScriptBlock added to your page, you must do so by either dragging it to your page from the Toolbox or typing it in manually. If you are using a RadScriptManager in place of ASP.NET's built-in ScriptManager control, you must register the required HttpHandler in your web.config in order for it to function properly. Instead of typing it in manually, you can do this quickly by clicking on the RadScriptManager in design view, selecting its context menu, and selecting "Register Telerik.Web.UI.WebResource.axd". This will add the reference in your web.config for you. For your convenience, I have added a screen shot here
I hope this was helpful. If you have any further questions, please don't hesitate to ask.