Wireless mouse stopped working with monitor USB port

Apparently the only "workaround" is to install Logitech Control Center, use it to pair the devices with the receiver, then uninstall the LCC software.

I tried both USB Overdrive and MouseSteer first, but neither seems to include the necessary pairing functionality. I uninstalled each, then found an older version of LCC (version 3.3.0) that was compatible with my operating system and processor, used it, took careful note of what and where it was installing on my system, used the included uninstaller, and voila!

Actually, there was some residual stuff that I dug up and deleted manually. I should mention that the LCC installer had a pretty good and thorough ReadMe that actually listed what files would be installed in what locations. It did omit a couple files that I found with a sudo find, but the whole thing was pretty painless.

And now I have a keyboard I like and a scroll-wheel on my mouse! I've been living in the dark ages with the one-button magic mouse for a long time :)

I think your problem is that USB is not carried over Display Port/DVI. I have an older Apple Cinema Display that has USB ports on it and the cable has both DVI and USB ends that get plugged into the Mac.

That DELL monitor has an upstream USB port (and I would be very surprised if that is not connected to your docking station for the PC). Connect a cable between that and the Mac and the keyboard and mouse should work.