The first issue that you are facing was not reproducible on my side. The zoomImage method seems to be working just fine. Please, find attached a sample project for you to test it on your side.
Saving the image on the server could be done using the saveImageOnServer client-side method. This method will trigger a postback to the server and save the image under the provided name. Please, refer to the client-side documentation on the ImageEditor for more information on the topic - http://www.telerik.com/help/aspnet-ajax/radimageeditor-client-side-api.html. Furthermore this approach is implemented in the attached sample project under the handleClientClick method.
As far as your third question is concerned, you can implement custom saving procedures in two ways. First approach is to utilize the ImageSaving server-side method, where you should cancel the default implementation and having access to the editableImage of the ImageEditor you can save it in any storage you want, providing a custom storage procedure. Refer to any of the following forum streams - http://www.telerik.com/community/forums/aspnet-ajax/image-editor/saveeditableimage.aspx, http://www.telerik.com/community/forums/aspnet-ajax/image-editor/server-side-override-of-buttons.aspx
The second method is to implement a custom image content provider as in the following help article - http://www.telerik.com/help/aspnet-ajax/radimageeditor-custom-image-provider.html
. Simply providing a custom implemenation for the SaveImage method will result in saving the image in any storage you wish to.
Hope this helps.
the Telerik team
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