it didn't work for Manjaro cause it was about Unity, not Xfce. There is
how to get rid of partition icons from an Xfce desktop, but there's a problem with that: you either remove all device icons from the desktop including your USB flash drives, USB HDD, etc. or disable automounting of selected partitions you don't want to see on your desktop.
I don't know about Manjaro, but Arch Linux it's based on is actually a mature Linux distro. It's just different from Ubuntu. Arch forces you to learn how things work. If something breaks there you'll have to learn how that thing actually works in order to get it fixed. Windows-like style of fixing problems - "click there, there and over there and pray those clicks make the issue fixed" - will almost never work on such distros. In practice if you're willing to learn, that approach isn't much harder than the Windows' one, it's just different. Also it gives you much more power over your OS. I've read on their web site that Manjaro is intended to be user friendly and everything. One should understand that 'user friendliness' here doesn't imply effortless. In my experience with such distros they basically implement an easy-to-use installer, cute desktop customizations and a handful of useful scripts for automation over the 'Base Distro' they derive from. But once you go beyond those scripts it's still the same 'Base Distro'. The farther beyond you go the more you realize that in order to get a fully automated system you must re-implement a good part of the layers. Much like OpenSuse, Ubuntu and the like did. So if I understand it right Manjaro is not an Ubuntu with the power of Arch, but is actually an Arch that's a bit easier to be introduced into.
Sorry to hear about your wrist. Hope you recover soon.