so you mean I can set SSID of main router and all Extenders in other rooms are the same? I was told by one friend as must set SSIS of extender different from the Main router SSID if not can cause...

1) Can I set SSID/PW same as Main router? So that I don't need to switch between main router area and another rooms which no /weak signals for main router but auto pick up by clients to powerline...