Any suggestions of Bahia places that either have hike-in camp sites, or car-camp sites that are good? Could you tell me some? How were the safety factors?

There's at leat one camping in Itapuã on the outskirts of Salvador. If memory serves,mthere's another Porto Seguro has at least two and of course there are camp sites within the Chapada Diamantina nnational park. That's about all I can think of, off the top of my head but there are certainly more.
Safety in the urban Coast of Bahia is always a big factor.
However if you go countryside there are well known hike-in camp sites that are safe.
Caraiva is a really great place to visit with a campground and very safe. It's a small fishing village in the south that's bordered by the ocean, a river and an indian reservation (Pataxo). Really special, small place where you would take a bus from Porto Seguro to a quick boat across the river and arrive directly in the middle of town (its one street). Jo (a French man living in Caraiva) is a great person for beta and can help you plan your stay. He has an eco-tourism company that works with the Pataxo to do day trips to the reservation, hiking, Corombau buggy trips and horse riding trips.