Unmounting a USB drive: Open drives object, mouse button 2 (right click?) on the USB drive, select Eject disk. wait until it disapears and any LED indicator on the stick stops flashing then remove it.
Things like external USB hard drives require the use of DFSee to have the LVM information installed. Once that is done it is a case of just plugging them in and they are available.
Adding and updating the original WSeB CD 2, and making it bootable, is the reason that UPDCD (UpdateCD) was created. It does all the work for you and you end up with a single bootable CD that has all the updates built in. Not sure where you can get it from at the moment though.
Edit: UPDCD260.ZIP is obtainable from
http://www.os2site.com/sw/upgrades/util/index.html you can also get the updcd261.zip which updates that there as well.