I don't understand what you really want to create.
If you want a standard iso on a live usb, get an iso in your normal install and point to it in order to get an install on the USB stick. With PCLinuxOS Live USB, your stick must be formatted to ext2 or ext3. The ext3 will allow persistance.
Do not login as root to perform your tasks. Always try to do them from a user session and root login to X will be used ultimately when there is no choice left. (desperate choice...
If you want to remaster your own system, there are plenty threads, docs, and advice at the main forum, a whole sub-forum is dedicated to this subject, you might want to go read a bit there.