Ned's fine. Just trying to get across that guns aren't all that impressive; dual-wielded NP machineguns (or a machinegun and rifle in the anime) are still inferior to Zero Berserker just drawing his damn sword. Basically, artefact sword > magic guns.

Yeah, that seems fine. Would also possibly make repeated fights more interesting.

C-Rank would read exactly the same, it just negates one rank less. Charisma's the one where you need to write a fancy description.