imperialscum said:

I think his primary goal was Luke. Everything else seems to be secondary and subordinate to that. If his primary goal was to destroy Alliance he wouldn't order fleet to hold while its star-fighter complement was wasted on rebels.

He orders the fleet to hold so they don't get destroyed by the blasts coming from that Death Star! Meanwhile, the fighters are there to make it look like the Imperials are actually attacking with their fleet. They're just keeping the Rebels busy until the DS opens fire.