Modulo C++, if you are in the right chair, I figure making a solid six takes less than a year and that's enough to do some heavy lifting. But it's hard to find a job where you'll get the right stimulus.

I'd back off on "compiler developer" - that's severely different from "compiler exploiter."

The way to avid all the ugly in the language is to have good habits. You only use the parts that work well. When I see things like Heartbleed, I think "poor guy never debugged a comms protocol in the wild in his life." That's one of those thing that's like combat - you have to defend a real product in the wild for a span of time before you "get it."