I love flying the JU-88.
With that said, it leaves a lot to be desired in defensive fire but this can be compensated for by knowing the arcs well and flying in a way to maximize the defensive potential.
Also flying in groups gives better protection if those flying with you know how to fly in a decent, non gaping hole wide formation. It was the mainstay of bomber protection in the war because it works well. More guns firing at a target increases the odds it will go down before doing serious harm. (yes i know its a no duh type response, but you'd be amazed how many people think they can solo bomber something with out support and complain because they get shot down.)
If you find your not nailing the targets as well as you'd like, also consider that the JU-88 can double as a dive bomber and does have dive flaps to help in this role. Yes it means more risk and may lead to you getting shot down trying to DB with it, but it can also lend itself to playing a GV support role.
The only bomber I fly more than the 88 is the B-17 but thats for long distance bomb raids.