Well I went through some of the same stuff as Rob, but with fewer side projects, and there are several issues, and QNX was one possible route, as you point out dying. I would look at eg Genode for something to work on in that kind of model instead, open source L4 based.
The big problem is GNU, that turned Linux into a bloated userspace, with often broken development processes which are only gradually being fixed. The whole busybox is, apart from the multicall binary thing, just about writing smaller tools. The hard solution is to rewrite userspace, which got us uClibc and later the far superior Musl libc. The easy solution is to use the BSDs, which basically just provide the core system without insane bloat, and with cross compiling and the core userspace already built in.
Meh. Your bloat is my usability. It's the difference between Emacs and vi: vi is smaller, also less usable, according to me, and I'm the only one whose opinions I trust in this matter.
The big problem is GNU, that turned Linux into a bloated userspace, with often broken development processes which are only gradually being fixed. The whole busybox is, apart from the multicall binary thing, just about writing smaller tools. The hard solution is to rewrite userspace, which got us uClibc and later the far superior Musl libc. The easy solution is to use the BSDs, which basically just provide the core system without insane bloat, and with cross compiling and the core userspace already built in.