So, I just ran into this problem, and I don't know if it's officially supported (probably not), but if you create a Request offering, and just pick whatever template, you can then export that management pack, and then change the template ID to be your Change
Request template.
<RequestOffering ID="Offering.GUID" InstanceName="Your Service Offering Title" Title="Your Service Offering Title" BriefDescription="Description of Service offering" Status="System.Offering.StatusEnum.Draft" TargetTemplate="Template.GUID" HideGotoRequestButton="false">
For example above "TargetTemplate="Template.GUID" You would change from the ID of whatever template you picked, to the ID of your change request template. Once you save this management pack, you can then re-import it, and then configure the rest
of the Request offering through the GUI.