Do you need permission to use the grill area and bbqs?

It is completely open to the public during park usage hours. The only caveat would be if it might already be reserved.

Bbq are a is open to public during open hours unless it has been reserved and that will be posted

Yes

Clearly marked

Areas that require reservations are clearly marked.

Nope sure don't, just asking as its not reserved for a group event.

No, as long as it's not reserved for a group event.

I not sure I think u csn use them anytime