Yes, you should be able to crab right beside your site, but that pier is only abut 20' from your site if you are in #104. A small path out to the pier runs between your site and site #100.
Try there at your site, pier, the Nature Center pier and also take a run out to the pier which is in the bay, just across the causeway.
The campground area is pretty large with 6 different campgrounds within the campground area - 1. Hoffman's (a few sites with power, pets and bath house), 2. Conoy (cabins), 3. Green's (power, pets and bath house), 4. Lanier with no services, but has Nature Center and bath house, 5. Malone that is pet friendly with no services with bath house, and 6. Tulip Loop that is FHU, pet friendly, but no bath house.
They utilize hosts from April until October, so they are always looking for hosts. While you are there, talk to Ranger Jonas Williams (there was a change at the end of this year, so I'm not sure who will be in charge of hosts next year). They will take you for weekends in the spring and fall, if you would be able to do that for a month or so.
If you check with any of the rangers, they should be able to tell you if any crabs are being pulled out of there, the where, and the when.
We hope you enjoy the park as much as we do....even in the summer with all the skeeters.