Ameya,
J_1IWRKCUS entries needs to be maintained in respective systems and can't be transported.It is a standard table and the issue that you are talking about is mainly about moving the table entries and not the table itself.As it is a standard table it will be available across the landscape.
Regarding changing of TMG settings,for this table you need to register the object and get the SCCR key.If SAP has designed this table to be maintained in respective systems,then let it be in the same way rather than fiddling with the TMG of standard table.
Let the Functional guy deal with this.
K.Kiran.