What should have happened for this story was to have Harry try to regain his dignity and respect (again), by funding some new project from the discovery of the symbiote. Something goes wrong with the experiment, Spidey saves the day, symbiote attaches itself to Peter in the process, and all is well for a while. Peter encounters the "New Goblin", while at the same time, the symbiote influences Peter with more agression towards Harry. MJ goes through her troubles, while "dark Peter" gets in trouble at work through Brock. Peter "pimp slaps" MJ, feels remorse, and immediately tears off the suit at the nearby church. Brock sees Peter in church shedding the suit, and voila... Venom.
Later on, Peter meets his match with Venom in battle, and Harry finally redeems himself to Peter by helping erradicate Venom by sacraficing himself. All of that could have been done without the Sandman element.
Even so, it seemed like old "Sandy" became dumber as he increased in size. Hence the groans and moans instead of words. He kind of reminded me of the mud monster he and Hydroman became at one point, when Sandman was at full size. Still, I thought it was a cop out that with all that power of being animated sand, he didn't take advantage of it.... All because he just wanted to cure his daughter.