2 quick questions

1) I am buying a battery Terminal from KnuKoncept

Battery Terminal

I have a 4guage power line from my amp and I need to attach it to the battery so I am getting a battery terminal. I notice that there are 2 existing power lines attached to the battery crimped into a connector attached to the battery. I am guessing I snip and seperate the 2 wires and attach them to the new battery terminal along with the power wire from the amp. Is that correct?

2) I am slipping a small board under the carpet in the trunk and attaching a small amp to the board. Will that be ok?

Thanks