Yes, and in prod I have a recover() handler that sends me an email with stack trace. Haven't gotten one in a few years...

Somewhere a spam filter thinks stack traces look like viagra ads.

Yes, except for the "defining them upfront" part, which sounds similar in theory to checked exceptions in Java. I'm very partial to this, especially in Go, where nobody ever bothers to propagate errors properly and instead just bubbles up the same `err` object all the way to the top.