Apart from the fact that these days you can hardly call C principal (yes, it's still used for the Linux and BSD kernels, but quite rarely for any new userland project at all), what are your main gripes with the API? It is well understood, stable, most people know its limitations, it's being used by most servers and clients on the Internet, so I'm curious why you call it "completely dangerous and unsafe".
As for the API, the entire permissions system is just a shit show (inflexible, setgid hack, no MAC, terrible ACL implementation), ioctl (hack job), signals (totally inconsistent handling), links (hard complexity), open(2) flag craziness, then the semi userland crap particularly PAM recently and anything which involves delegated permissions from yp/nis/ldap. Urgh it's hell.
I'd rather write win32 if I'm honest these days. At least they have the honesty to break the API when it's dead by adding Ex on the end of a new one.
You might need to train yourself to ignore the ads blinking at you from your start menu and taskbar though.