Hi Gabbe,
i use 5 engineers on Opro2, +11 bve, and you should run with bulge + 0.6 belt armor (in this 3 guns configuration no deck at all) 26/44 knots. I think this is the best configuration: You got speed, enough firepower (i assume you got some decent Gunners :D ) and the ship has enough turn speed to dodge properly.

I dont use to AW the opro2 for the next reasons:
a) KM armor is expensive;
b) KM armor isn´t good enough to pay it for;
c) If you go fat, you are easy food in this BC, you need speed to avoid BB4,5 or 6 to hit you.

I hope this helps you :)

Ben

hmm thats really nice :) , i got 4 enginers now,
1x elite boosted lvl 90 ,
1x +12 boosted lvl 85
1x +11 boosted lvl 84
1x +9 boosted lvl 76

and im at 24/39 OH really want more but .. yeahh you know :P