Okay, so after some experimenting and lots of Googling I figured out what the error here was. Packagekit needs libsystemd as a runtime dependency (see:
http://without-systemd.org/wiki/index.php/Boycottsystemd.org). If libsystemd is not available, the process fails with an unknown error code. To test this, run `/usr/lib/Packagekit/packagekitd`. As this binary cannot start, packagekit itself crashes meaning other applications like apper are completely useless. While not a big deal (I'd assume anyone who was able to install Obarun to begin with should be able to deal with using pacman) it is something to look into I suppose. I don't know much about how packagekit works, so I have no clue if there is a way to build it to not need libsystemd, but if there isn't a way I'd suggest trying to block it. I'm going to experiment with adding Artix's "libsystemd-dummy" package to see if it even works here.
EDIT: After reading this post
https://forum.obarun.org/viewtopic.php?id=379 I think the best course of action would probably be just to figure out how to block packagekit. Gotta love how so many packages claim to not need systemd as a dependency but then don't work when it isn't installed lol.
EDIT: Well after looking at the packagekit source, it appears systemd may not be necessary. I'm building it now to see.
EDIT: This should be my last update. Yes, packagekit can be built without systemd support (despite what without-systemd.org says). All that needs to be done is adding `--enable-systemd=no` to the list of options in PKGBUILD. Funny how much more I feel like I'm learning with this system, feels like even more than I did with Gentoo. This is an awesome system, and I'm tempted to compile a list of packages that can (or can't) be built without systemd support to help new users down the road. Depends on how much free time I have for it.