We use kali for pen testing, not as a daily driver. I work in infosec and use OpenBSD as a workstation, bootable kali on a thumb drive for when I need some bigger tools.

Does ZSH still contain a ftp client? If you like minimal you should check out OpenBSD's ksh (oksh on arch maybe?), it behaves exactly the same way bash does (for me) and things like dd if=/dev/mm<tab> actually work, which iirc still doesn't on zsh.. :}