Indeed, for me the only things I REALLY like about an indoor range are strong, solid, lane dividers and constantly circulating air. In my opinion there really isn't a design feature to make a range "feel safe" but it's more of a welcoming and friendly staff plus a decent amount of privacy that makes me feel at ease at the range. The only time I didn't feel completely at ease on the firing line was an indoor range where the guy at the counter acted like he was doing me some huge favor to rent a handgun, the RSO looked like he would rather shoot himself in the foot then hang around one more minute, and they kept calling random cease-fires that would last 15-20 minutes so the RSO could go disappear somewhere. It's less of a facility issue, and more of a staffing one.
RangeDS: Looking at the Lake Norman location there is nothing offhand that would put me off, it all looks very clean. I don't live too far away, I'll have to come out sometime and check it out.