If you rly want have 6 guns on normal VHF .. take 4x ancient cannon and 2 guns with proj. speed 750. You can mix it also on some ships (like Komodo dragon) with turrets so in the end you can have up to 8 projectile weapons and still perfectly working aim cross
NPCs not use missiles, cds aggressively, they not turn so fast. NPCs killing will give you good aim and can help with learn avoid better guns fire. But for pvp you need practise it on-line ...