Any player getting his a Ju-88 to the city strat and back alive can call himself lucky, considering his rides speed, attainable altitude and defensive armament.
It's not much better with attacks on CV's, a Ju 88 is very close to being dead meat on the table for every enemy fighter it runs across.
Attacking an Airfields Town's largest cluster will yield very good perks, as for Strat targets they are impossible now a days to hit, unless with long range 4E's.
Carriers are generally uncapped, I would say a good 75% are never capped let alone with fighters around 10-12k which yields the best chance to hit a CV, granted any fighter even at 6k can catch the buffs RTB, but I have still gotten over 15perks for sinking a CV in 88s and all planes were shot down.
I do CAP a CV myself, however last tour alone I racked up roughly 500 perks in Buffs just sinking carriers with high ENY buffs from Betties to Ju88s.
The Key is to find specific maps like the one where v85 is practically next to a Port, just about every hour you can sink the CV based on how close it is.