Don't have anything to add to this except to say thanks to the team for an amazing product. Been using fish shell for 5+ years now and I love it. "Finally, a command line shell for the 90s"!
Sort of a combination finger-trap/cigar cutter for newbies.
> rking's personal recommendation is to go ahead and use set -e, but beware of possible gotchas. It has useful semantics, so to exclude it from the toolbox is to give into FUD.
Manual error handling would be ideal but it's too easy for me to mess up and miss something. Plus, if you really wanted to catch everything with proper error handling you would need to wrap every command in your script.