is password required to extract certs and mac

Hello,

I am newbie.  

Couple questions, please help.

1. Is login password to modem required in order to extract certs and mac? using the tool JTAG utility and cmnonexpv
2. in order to use JTAG utility, do i have to buy JTAG hardware component and solder it to modem? what is JTAG component to use with sb6141? may i have link please.
2. For a working sub modem, if i extra cert and mac, will this modem become unusable?
3. I see people saying full dump, what is dump? 

Thank you