aahhh ... allow me to advise
focused medium suppose to have high damage but its tracking will not make it for the small rats in lv2. focused med will be good for cruisers which is slower. use small medium beam, the tracking (0.1) makes the strikes almost 100% hits. the medium turrets tracks well if you can kill them before they get to orbit you, far out at 20-30km. but by the time you get 1, chances are 2-3 have started to web you.
my omen for mission lv2 :
1) 4x medium beam (small) + microwave or anything with em+therm (not radio), hit distance 10-15km is good. lv2 rats like to orbit u at 1km-15km
2) 1x light missile (fit ammo spec for rats explo,therm.etc). make this an assault launcher or better if you have
3) med slots are rats spec shield hardeners x2, +1 small T2 booster
4) low-slots : i try to put as many pds here, whichwill leave 1-2 slot for add on armor or other hull upgrades if u like.
in all the turret testing, it seems tracking is the most important factor in securing a hit on the target. so you may also consider having tracking enhancement slot for low slot if the hits are awis on and off 2-4 hits outa 5 kind.
comparatively, i have also tried the following :
a focused med pulse(microwave) vs 250mm arty(nuclear depleted), 250mm tracks better than the laser, all hits 100% against lv4 mission frigs. the laser hits more damage, but misses all the time. each is enhanced by 1x tracking enhancer
for enhancing pulse laser 100% hit setup i have to use 2 tracking enhancers n 2x webs, ab in close 2xweb and pulse spam them. this one will also work. but for level 2, your caps will prob have to goto healing of ship hp, so ab will be bad idea.
for comparison :
med laser/focused med pulse in amarr = heavy missile in caldy
large laser/mega pulse = cruise/torps
so heavy missiles are not very efficient against small ships
when i got my omen approx 3mil isk (4 turrets), i used it to mine for my prophecy approx 22mil isk (6turrets), when i got my prophecy i use it to mine for my apoc approx 99mil isk (8 turrets). now i got apoc, i use it to farm pve. now pve is to farm good standings for good station ore -reprocess rates, and farm jumpclone for future if you goto low sec mining (save yourselves in case your pod-egg gets pooped). and farm pve gives you an idea of what combat crap to expect in low sec. its helps even for miners. i also use the prophecy to farm for all my 4units of +3 implants
ask ashurn about mining rates, theres a calculator file he made. generally a prophecy mines > a retriever miner. and a prophecy 6xminer2 + 1 light misile + scout drones = self sustained in 0.6-0.8 belts. i wud sugest using this as a intermediate stage before going to covetor. an in between till the skills comes out. either way, you should pump drones training for good self defense even for future use in covetor n hulk.