The park hours are still not posted on the site but from what I remember, October's hours are usually till 6pm, excluding the HHN.
I would check with the concierge about birthday extras at the resort's restaurants.
We celebrated my son's 8th birthday at the Hard Rock Cafe. The make the birthday child stand on a seat or a high platform with a birthday sundae while the entire staff and diners serenade them. I still have the greatest picture of my son just relishing in all the attention!
What a great place to celebrate a 6th birthday! Have a great time.