@mattb66 The simple answer is yes, it is safe to remove pamac. I did it two or three yaers ago, and have no problem to run Antergos without pamac.
In the past, I’ve also did another test. I’ve removed pamac from Antergos-Kde, Mate, Cinnamon, Gnome3, and replaced it by octopi. Octopi worked very well in all DEs in place of pamac.
For a long time I don’t have neither octopi. No graphical frontend is as reliable as pacman itself. Let’s continue to speak only in native pacman’s terms.
Trying to answer you, I’ve installed pamac in Antergos-Kde Testing environment. This is what pacman is going to remove along with pamac:
└─> sudo pacman -Rcnsu pamac
Package (12) Old Version Net Change
antergos-kde-setup 1.0-3 -0.48 MiB
appstream-glib 0.7.2-1 -2.80 MiB
archlinux-appstream-data 20171017-1 -17.58 MiB
gcab 0.7+16+g4bc4be1-1 -0.35 MiB
libappindicator-gtk3 12.10.0-12 -0.18 MiB
libdbusmenu-gtk3 16.04.0-2 -0.17 MiB
libindicator-gtk3 12.10.1-7 -0.12 MiB
pamac-tray-appindicator 6.2.1-1 -0.08 MiB
qtcurve-kde 1.9.1-1 -1.08 MiB
vte-common 0.50.2-1 0.00 MiB
vte3 0.50.2-1 -1.35 MiB
pamac 6.2.1-1 -2.38 MiB
Total Removed Size: 26.58 MiB
:: Do you want to remove these packages? [Y/n] No, thanks
This list is almost identical to yours. The main difference is the absence of antergos-kde-setup metapackage in your list. Unfortunately, pamac makes part of it, so full pamac removal should remove antergos-kde-setup as well - thus, breaking Antergos Kde integrity. I don’t understand, why antergos-kde-setup is absent in your case.
I’m also slightly worried about qtcurve-kde removal. It’s a very common Kde style. It may be re-installed later though.
Other removal candidates seem to be Gtk3-related, so probably may be safely wiped out of Kde.
Installing octopi without removing pamac first wasn’t a good idea. Two graphical frontends might have some common dependencies (it’s hardly possible, but who knows), so some octopi deps might be present in pamac’s removal candidates.
What does this command return for you?
sudo pacman -Rcnsu pamac