Remember that for any high slot on a Rupture not fitted with big ass weapons, somewhere in the world a Brutor gets a heartattack...
Idi Amin is Brutor
Anyway - on drones vs missiles vs guns:
If you put 6 mil SP into Drones, they will shred things(*) as you'll have nearly maxed out T2 drones.
If you put 6mil SP into Gunnery, you will shred things(*) as you'll have nearly maxed out T2 guns.
If you put 3mil SP into Missiles, you will still be a bumgay caldari pilot.
I used to mission run with a Dual-repping/Cap injecting, Afterburning Machariel. Close in on things at 1km/s, web and shred with T2 800mm AC's, and move on. Not the safest, or most efficient, but Pimp as Hell. Taii was a CNR fan, Domi's with heavies / sentries rock, Tempests with Artillery and shield tanks work. Etc Etc.
Most ships however have room for at least 1 flight of lights, and one of mediums. Make sure youare packing these for L4 missions, as your Arties can't hit tackling frigates and it's embarrasing to have 200m of BS held in place by 150k worth of shitty frigate.
Some misisons have faster HAC type cruiseres that like to orbit you at 2km too, Arties can have trouble there. You either have to Mess with their radial vector (Kiting) or swap to AC's, though if you are in a slow ship (Maelstrom) this could be harder work than it sounds.
The trick is to get to a point where you can do them comfortably then as you soak up the cash, then cross-train for PewPew!
nb: Things (noun) ships of the correct size given your weapon choices, ammunition, range and tracking.