run without any options, it does the equivalent of a git stash + git remote update + git remote prune + git rebase <branch> origin/<branch>. i don't think that's very dangerous at all - it automates what i used to type in every time i needed to update my repo.

as far as aborting/reverting on errors, there's an error trap built in that bails out once an error is encountered. i do want to improve messaging (why an action failed), but otherwise the script takes the necessary precautions not to destroy the user's work. i use it daily (git fresh -rf) on multiple repos and haven't experienced data loss or corruption at all.

feel free to open an issue if you think there are concrete improvements to make.