I've lived in SC for eight years. Prior to coming here, I had spent my whole adult life in NH, some of that in the "outskirts of Concord."
First I'll address what seems to be your primary concern, crime. When I moved down, I checked the homicide rates. SC was seven times higher per capita than NH! It is reasonable to assume the non homicide violent crime rates are a similar ratio. More recent info attached.
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NH is finally Constitutional Carry. SC tried last year but we'll have to get a few more RINO Senators to take the Hugh Leatherman conversion. (He was a Senator who finally died.) To get a CWP, you'll have to take a day long class. Complete waste of time for anyone already familiar with firearms. Find a class & wait for an opening. The live fire requirements are waived for veterans. Then put together your application including fingerprints. They are required to issue within 90 days but if you wear a badge, requirements are really only suggestions. They will look at your application for the first time around day 80. Or maybe day 84. Awe hell. They'll open it up whenever they feel like it. Who are they kidding. At least they dropped the $50 licensing fee. Until you have the CWP, you can keep a loaded pistol in your glove box or console of your car, just don't bring it out. You can get jammed up. See
@Mike Islander for the money quote, "The part of town you chose, and the company you keep, will determine your risk."
I think the last property tax bill in NH was around $6,500. SC the following year was around $750 for a lesser valued home in SC. Your real estate dollars go a lot further in SC. If we could have put our NH house on a flatbed and brought it to SC, it would have dropped 30-35% once here.
NH has no sales or income tax unless some of your income is interest or dividends. SC is nominally 7% on both. Counties can increase the sales tax. Between the two states, it almost comes out in the wash but yes, SC spends more than NH.
Down Augusta way, it can definitely get a bit hot and sticky in the summer. A light jacket will be fine for winter. I'm up in the NW corner of SC and summers are a bit more tolerable because I'm out of the lowlands with a bit of elevation. Winter is a joke compared to NH. Just a chance of flurries will shut everything down. I do mean everything. The most I've seen is 5". Some winters none but one storm with 2-4" is about average.
I'm guessing you're into shooting. SC has a fair number of public shooting ranges and apparently a 100 yard rifle range and a pistol bay seems to be enough for most people. That means fewer private clubs but there are a few in that area where you can stretch it out a bit further.
Best of luck!