I use a wired Apple keyboard and mouse (posh Kensington Expert Mouse trackball actually - it's my favorite for 25+ years). The Lightning cable is usually used with your keyboard and mouse only to charge their internal battery - they connect to the computer wirelessly over BlueTooth. No cables needed! But I use wired because I don't want to deal with recharging the battery and my keyboard never moves, so...
You can absolutely use just about any USB hub you want on the Mac Pro, and only the cheapest and crappiest ones won't be able to recharge your keyboard and mouse using the Lightning cable. I like to stick to name brands like Belkin and D-Link, and they have never failed me. I've been using Belkin hubs for more than 20 years with no problems. I always use and recommend "powered" USB hubs that come with their own AC adaptor (wall wart). That way there will be no issues with devices needing too much power. Passive (non-powered) hubs only pass the power from the computer's USB ports down to the connected devices, and if you're dividing the power from one Mac Pro USB port into four connected devices it is possible you'll get a "low power" alert on the computer screen. (It is practically impossible to physically damage anything, so don't worry about that).
I currently have six USB hubs on my Mac Pro:
- Two D-Link four-port powered USB3 hubs, daisy-chained (in other words, the second hub plugged into a port on the first hub so they only use one of the Mac Pro's USB ports, giving a total of seven ports available across two hubs while using only one Mac Pro port) = connects things like USB3 hard drives, Virus TI, Linnstrument, and other data-hungry and power-hungry devices. One port from the second hub goes to a USB Extender which uses a little box on either end and a CAT5 cable connecting the two - this lets me do a long (30-foot) run across the room to my guitar/synth rack. On the far end the extender connects to yet another Belkin powered 7-port USB2 hub to which I connect all the stuff in the guitar/synth rack - Line6 Pod, Roland VG-99, Eventide H9, Dave Smith Pro-2, and another Unitor MIDI interface to deal with other synths, the EuroRack setup, etc. So that stuff in the guitar/synth rack is at the far end of two USB hubs (one USB3 and one USB2) with a USB>CAT5 cable extender in between. It sounds crazy but it all works just fine.
- Three Belkin four-port USB2 hubs (two of them daisy-chained and one running solo) = the solo hub is for computer keyboard (with the trackball plugged into the keyboard itself so it doesn't use up a port on the hub), PreSonus FaderPort, a Unitor8mk2 MIDI interface, and my main MIDI keyboard (M-Audio Keystation 88 plugged in via USB). The two daisy-chained hubs are only for dongles - three iLok2 and three e-Licenser dongles, with the last port used for connecting to the Dynaudio AIR Control or Genelec GLM system to configure my speakers from the computer.
This leaves me one empty USB port on the back of the Mac Pro in case I get a new device and want to experiment before I decide where to plug it in.
You can feel free to daisy-chain USB hubs pretty much any way you want. The only thing to be aware of is that USB2 is much slower than USB3 (and USBv1 is slower still), so if you plug a USB2 hub into the computer, anything that's "downstream" of that hub will run at USB2 speed - so don't go Computer > USB2 hub > USB3 hub or the USB3 hub will be only passing data at USB2 speed. The other way around is fine - Computer > USB3 hub > USB2 hub. Just keep in mind that a USB2 hub will choke anything that passes through it down to USB2 speeds. No biggie really, and you won't damage anything by trying out various configurations. I even have a few 20-year-old Belkin powered 7-port USBv1.1 hubs lying around and I can use them just fine, mixed in with the more modern ones, but they are really only suitable for simple stuff like iLok, keyboard, trackball, etc.
When I first got the Mac Pro cylinders I wanted some bad-ass, all-metal USB3 hubs with huge power supplies, and I found some online and bought them - only to find out that they required you to manually push the power button every time you powered up the room in order to turn them on. (Not all of them do, but the ones I bought did. I'm an idiot.) So I just went down to my local and bought some simple D-Link and Belkin hubs and they work just fine. There are, however, lots of cool hubs with 7 or more ports, individual power switches per port, etc. Check on Amazon or MonoPrice to see the crazy variety available.
If you need to extend USB cables beyond the basic 15-foot limit, look for an extender solution that uses a CAT5 cable in between two little boxes - these usually don't have their own power supply, but do require that they're plugged into a powered port - either on the back of the Mac or on a well-powered USB hub. This is similar to what I use:
https://www.monoprice.com/product?p..._1JACn-FpydavWfiMed3-T-X4yUv9K3BoCqWkQAvD_BwE