There are some pull thru sites that can accommodate big rigs. Look at the site map and the camp hosts are really nice and can get you a reservation that fits you.

Definitely, but some better than others. If you reserve through Recreation.gov you can get site details including pad length. I find these to be generally accurate. All of the sites have a concrete "landing pad", generally around 25ft, with asphalt before/after. Depending on asphalt before/after concrete pad you may/may not need to level up long (>30ft) rigs.

Yes but you will have to check which sites within the campground can handle a setup like that. I recommend calling them to be sure. They’re very helpful.