Do I need to insert a sim to the phone for enable simulate sim option? Or without sim it can do? Another question with "phone blocked when power on" phones can I use Simsim?
...without simcard is working. Only first need to enter in the Service Mode or Normal Mode.
About your second question, I not tested this option. Maybe yes, maybe not. Try it, you not damage your phone. If not working, unlock your phone using testpoint procedure (if in your phone firmware is hight).
dagos