There may be other unforeseen breakage primarily in the handbook portion of the wiki.
The Table Of Contents section of each "PC-BSD® Users Handbook" page may be the best workaround.
Talk:Burning the Installation Media
helpful for USB sticks
no need to zero the entire thing, can be a limited zero that will be as effective- dd if=/dev/zero of=/dev/usbstick bs=1024 count=10
If KDE or Dolphin or Device Notifier succeed to mount a USB stick but you cannot unmount it, even when you are not actively using it, switch to root and then issue the shell command.
A USB stick can be subdivided as any other HDD could: first gpart create, then newfs. So, gpart create -s MBR /dev/usbstick then gpart add -t freebsd -s <size you want> /dev/usbstick and finally, mount -t ufs /dev/usbstick /mount/point.
Of course the above is generic and some adjustments are needed.