FYI: Dennis did symlinks before Joy did and it was 4.1a where they first show up in the BSD stream

As for shebang, the idiom was recognized by the shell in user space in 1.0 BSD, when the precursor to cshell (the Berkeley shell) was released -  but it took a while to make it into the kernel as recognized look-a-side to be more automatic.   My >>memory<< is we had it in the 2BSD release, but it might not have been added until 3BSD - look at the exec.c code in the BSD kernels which frankly I'm too lazy tonight to do myself.