Can I remove the ability to delete or Change transaction templates so other users can't delete or change them?

At this time, we don’t have a capability to lock templates from being changed by others.

You may wish to discuss with your company administrator about changing the Settings for the workgroup you are making your templates in. We can change the settings so that only the person who creates the template in that workgroup can view / edit the template going forward. However if a workgroup shares templates between users, then this option is likely applicable.