I use Bash for scripts, though my interactive shell is Fish.
Usually I use #!/usr/bin/env bash as shebang. This has the advantage of searching your PATH for Bash instead of hardcoding it.
My folders are only differentiated by those in my PATH and those not.
Most of my scripts can be found here. They are purely desktop use, no syncing to any servers. Most would be useless there.
For good practice, I’d recommend using set -euo pipefail to make Bash slightly less insane and use shellcheck to check for issues.
This is personal preference, but you could avoid Bashisms like [[ and stick to POSIX sh. (Use #!/usr/bin/env sh then.)
With shortened commands the risk is that you might forget how the full command works. How reliant you want to be on those commands being present is up to you. I wouldn’t implement them as scripts though, just simple aliases instead.
Scripts only make sense if you want to do something slightly more complex over multiple lines for readability.