The working, is : Logitech ITouch P/N 867063-0104 ( White multimedia, with two USB ports, that don't work in the X5000 ( "low voltage level" appears in workbench). But works in PC. I think there's a problem with USB, at least in my board.
No, your USB ports are fine. Thing is, each USB 2.0 port is usually specified to deliver 500mA current in total, which it tells the operating system. The OS then has to make sure, this maximum is never exceeded as it might simply burn your board (its power traces), if too much current is drawn. But continue reading before jumping to conclusions
For your keyboard with its integrated hub it seems there is already so much current drawn, that most additionally connected devices cause this maximum to be exceeded. Hence, AmigaOS (more specifically the USB stack in AmigaOS) is refusing to attach (and power) those devices to protect your hardware.
In PC/Mac world, the operating systems just don't care, but rely on resettable fuses on each USB port, to limit the current drawn. By designing the hardware for a higher maximum current than the specification allows and a "don't care" software approach, they are supporting all sorts of devices which don't comply to the USB specification and require more than 500mA.
In addition there are certain "workarounds" and meanwhile also specifications to allow devices to recognize A/C wall chargers which deliver higher currents. But those involve shortening the USB data pins in one way or another, hence you can either load at higher pace OR transfer data. In contrast, Apple i-Devices do some more magic, allowing the device to draw even up to 1.8A from a USB data port to allow quicker charging, while at the same time allowing for data transfers. But AFAIK this only works with Mac and not PC as host.
In Amiga world, we don't really know if all hardware manufacturers implemented resettable fuses for their USB ports. So if we (the OS) would just don't care and rely on the hardware, it might be that said hardware is fried, just by connecting a non-compliant USB device trying to draw way too much current. Best case would be the resettable fuse activates and the device just doesn't work. Worse case, the fuse is not resettable, gets destroyed and you have to solder a new one to make the USB port work again. And worst case would obviously be no fuse at all, meaning from power traces over USB controllers to everything else could just burn. If that happens in PC world, you just go to your next radio shack and get yourself a new mainboard for 50 bucks, where in Amiga world you might have to invest several hundreds if not thousands for a replacement, if the damage is unrepairable. Who would like to take this chance if a self-powered hub is so much cheaper?