Obviously, to each their own, but to me, this is an overwhelming amount of commands to remember on top of all the ones they are composed of that you will likely need to know anyway — regardless if all the custom ones exist.
Like, I'd have to remember both `prettypath` and `sed`, and given that there's hardly any chance I'll not need `sed` in other situations, I now need to remember two commands instead of one.
On top of that `prettypath` only does s/:/\\n/ on my path, not on other strings, making its use extremely narrow. But generally doing search and replace in a string is incredibly useful, so I'd personally rather just use `sed` directly and become more comfortable with it. (Or `perl`, but the point is the same.)
As I said, that's obviously just my opinion, if loads of custom scripts/commands works for you, all the more power to you!