NO! Do NOT treat with a weed/feed first. The nitrogen you put down goes to the soil that your sod will sit on. It will burn the sod up.
If you are laying sod, do not put a fertilizer or weed/feed on it for the first 90 days.
I would recommend laying down a thin layer of compost before sodding. If you have black clay soil, lay down some expanded shale then put the sod over the top of that. The more shale you put down, the better it will help your turf. The expanded shale (sold by the bag at places like Calloways or Natural Gardener) will give you moisture retention at the root zone while expansion/contraction properties which keep your black clay from compacting.
I would not bleach the limestone. In fact, I might not even pre-treat with anything. We just finished doing this to a limestone home here in DFW and needed no help other than a power washer. That said, we use nothing less than a 3000 PSI power washer. It will get the job done. Be careful with it though. You run that wand across your toes and you'll lose those toes.