Why BSD over Linux? And which BSD would you start with? I'd stay far away from SELinux, knowing that added complexity is unlikely to add security in practice.

Why BSD over Linux? And which BSD would you start with? I'd stay far away from SELinux, knowing that added complexity is unlikely to add security in practice. But is any of the major BSD kernels appreciably simpler or more secure than the Linux kernel these days? I'm sure that the Linux kernel has broader hardware support; that would yield an OS that more people can actually run without restricting their hardware choices. So on balance, Linux seems to me like a better choice. To be sure, I'd strip down the userland, starting with the C library; I'd choose musl over glibc. Actually, my idea of a "trustworthy", "hardened" Linux distro would look a lot like Alpine Linux (the in-development musl-based version).