Moving resources from one subscription to another is just a management plane change, there is no change to the data plane so your data isn't actually moved anywhere. There really should be no risk involved as if the move fails to complete then your resources will remain in the original location. All dependent resources need to be moved together, there's no way around this.
You said your old subscription has expired, do you mean you have run out of credits and the subscription is disabled? If this is the case then you will not be able to move those resources. You will have to reactivate that subscription first before the resources are available to be moved.