Rog,
I think you'll have a great time. Last time I went snapper fishing it was on a half-day trip and we didn't have much luck. If you do a full day I think your chances are much better.
It is a big park. The nearest campsites to the beach are on a loop that's not even on the map posted on the website which run along the little canal. Look at the map here
http://www.alapark.com/parks/pdfs/gulf/gulfcampgroundmap.pdf and the cul-de-sac showing sites 4-16 has been extended back to the left towards Lake Selby (?) and these are the closest to the beach (5 min walk). Along this extension by the canal are all pull throughs, full hook ups, no trees, and gators in the canal (if you bring a little dog don't leave him outside overnight

) . No bathhouse along the extension either (although there is a vacant piece of land for a future one) so the nearest one would be the box on the map by sites 1-3. To get to the beach you walk to the end of the extended loop across a footbridge out to Park Road 2, turn left, walk across the canal and in less than 5 min you're at the beach. This part of the beach has no facilities, just a lovely stretch of sand. Just to the east within view is the Beach Pavilion with has concessions, bathrooms, etc which you can park at for a reduced fee since you're at the campground.
Gulf was a beautiful, lush, heavily shaded park until the hurricanes of the last couple years and now it is wide open. It has beautiful sunsets along Middle Lake. I've been going there for 30 years as a kid now a dad and I love the fact it's a little sleepy beach town without the glitz and glamour of, say, a Destin. Great places to eat but the beach is the main attraction. We drive go-carts, go to the cheese farm, spend time on the beach, eat out once or twice, hit the souvenir shops, see a movie. The park is connected to the Backcountry Trail which is a paved biking/walking trail about 4-5 miles in length towards the town of Orange Beach with a Y-that turns it into a 10-miler if desired.
If you end up going PM me and I'll tell you where to eat, shop, buy groceries, etc. We go to Gulf twice a year now - once in the late spring early summer and once in November when the town just north of Gulf Shores (Foley) has a 5k run (The Oyster Run) with the best post run food I've seen. Where else can you run a 5k, eat fresh shucked oysters, pizza, and beer all by 10 a.m.? I mean is that great or what?
The pier is still not ready - still being built. It's longer-bigger-better but it was built to pop boards loose but save the infrastructure and as they've built it every storm that came along has popped a few boards. They're making headway but I haven't heard of it being finished yet. We're going down Memorial Monday and leaving out Friday morning so we would miss you by a few days but like I said if you plan to go PM me and I'll fill you in.
Enjoy!
Bama ED
PS-my wife (whose idea of roughing it is spending the night at a Holiday Inn) says Gulf has the cleanest state park restroom/bathhouses she's ever seen in a state park. So we love it, recommend it, and encourage staying there.