I am struggling to figure out whether the namespace created without limit-range can resources use up to maximum possible leaving issues for other namespaces.?
A LimitRange provides constraints that can:
Enforce minimum and maximum computing resources usage per Pod or Container in a namespace.
Enforce minimum and maximum storage request per PersistentVolumeClaim in a namespace.
Enforce a ratio between request and limit for a resource in a namespace.
So if a namespace is created without LimitRange there are no constraints and you can't enforce the use of minimum and maximum per Pod.
For more details, check the link: