Hi Sally,
Currently, there is no definite way in order to avoid getting any RateExceededErrors when using the TargetingIdeaService since the said error would depend on the overall traffic of that service. What we can recommend as of now is to handle the error and retry your request as stated in this
guide.
As for the BatchJobService, this service usually support requests that involves mutate operations, meaning it could only currently accommodate requests that either add, update, or remove objects in bulk. The TargetingIdeaService, being that it is a service that specializes in generating suggestions, is currently not supported due to its difference in its purpose and usage.
Thanks and regards,
Peter
AdWords API Team