Seems fine. Give it a try
No. See here how to install it. BTW, I do not want to force you to use Homebrew. There are other package managers, like MacPorts. So feel free to use whichever you want.
perl is installed on every macOS, as well as ruby and python etc. But if you are using a scripting language regularly I wouldn't meddle too much with the ones installed by default, because these are going to be used by other programs and maybe even the system itself. In addition the preinstalled versions are rarely up-to-date.
type -a perl
you can see all installed perl versions.