I would direct you to this thread:
https://www.city-data.com/forum/new-...le-female.html Has a lot of relevant info on your exact concerns.
I was born in South Jersey and lived here majority of my life, live here now. You have the right idea focusing on this part of NJ to get the best value and be a little closer to NC, but honestly, I think it's kind of silly to focus on the actual NJ border. You're talking about 15-20 minutes in time savings on a trip to NC. For example, to get from Audubon/Haddon Heights area to Delaware Memorial Bridge takes around 30 minutes via 295 or Turnpike, and there's rarely any traffic that far down aside from a little around Exit 28. And if you want to avoid any traffic at all, you can pay $2-3 and take Turnpike. Many of the homes down in Salem/Woodstown area which is more spread out are 10+ minutes from the highway so you're talking about shaving 20 minutes, 25 max off your GPS on a 7-8 (?) hour drive.
If you want a specific town that has top safety, is clean/nice-looking, and very close to highways going south, I would recommend Haddon Heights. There are a lot of homes there that have small apartments on the second floor, back addition, etc, for reasonable prices. May be tough to find one now, but you might get lucky. Audubon and Barrington (and most surrounding towns) would also fit that bill. So would Runnemede, though personally I don't like it as much. It's not at all bad though. Who knows, maybe you will like the area or circumstances will change and you'll stay longer, so it may as well be a town you like.
But if you'll really barely ever be here and definitely aren't staying no matter what, I guess it doesn't matter. The only areas down that way that seem/are a little/moderately dicey are Penns Grove, parts of Salem City and Bridgeton. Not to say I'd be scared to live there but I'm also a younger guy, bigger than average, etc. But I definitely wouldn't seek out living there, myself. I would wager that the general area you're looking at is
slightly less safe than the area I mentioned (mainly due to lower economic opportunity, probably more drugs, etc.), but not dangerous. I would characterize the area you're looking at by farming and 'post-industry' (chemical and oil refining that isn't as big as it used to be). It isn't really in Wilmington's orbit at all despite the proximity (and Wilmington is pretty sucky/limited as a city anyway; banks, law firms, and DuPont, that's about it).
Woodstown is safe and nice but is pretty slow-moving, unless that's what you're looking for. Not a whole lot going on economically or otherwise. Again, it's a farming/agricultural area. Plenty of nice properties though. Really depends what your priorities are. Other than Woodstown I'd probably consider Pennsville and Swedesboro if you're sticking to that area.
Pretty much everywhere in South Jersey is safe except for Camden (large parts of which aren't all that dangerous lately) and a few other pockets (mainly specific apartment complexes in certain towns). Most towns have little and usually very minor property crime (stolen bikes, stolen change from cup holders, shoplifting, etc.) and almost no violent crime. Rents here have been crazy since covid, but are still well within your budget for what you're looking for, in pretty much every town. Rents are usually a couple hundred more now than what people were asking pre-covid. Basically, people aren't leaving their rentals because purchase prices are too high, so the supply of rentals is low. I manage a small apartment building so I know. Pretty much everywhere is clean also (except much of Camden, and the 'dicey' places I mentioned, which have a lot of homes in disrepair)? I guess that depends on the specific property. There are some grittier towns here and there though (Paulsboro, parts of Gloucester City, etc.) that don't look as good as the others.