exeterdad, thank you. After putting /sbin/vwireless in sudoers, I can use it from a command line as normal user without require root's password. ifconfig, iwconfig, and dhcpcd also work fine with non-root user. However, /path/to/wifi-radar (/usr/sbin/wifi-radar, IIRC not in front of Vector at the moment) is likewise in sudoers, but still asks for password.
As for kde being called...I don't have any extra KDE programs installed. The only desktop environments installed are XFCE, fluxbox, MWM, TWM (and I've only used the 1st two) all of which were installed from the Standard installation CD. Anyway, after starting wifi-radar, htop showed kdesu (it may have been kdesud) and a couple of other KDE-related things. I'll have to check again when I'm on the Vector laptop.