A huge step for me forward:
I checked in FreeBSD's search services and found out how to use su with the originally set ,during the installation, user (jv in my case ) ,I could not use thus far, has to be added in "wheel" in /etc/group file, so that now I can simply use the xterm as jv, su to root and: #xsane and up the scanner comes fast as a blitz.
I do not have to log out and login as root to use it and then log out again and login as jv to continue my work.
It is not perfect but very handy. Until I try another scanner the Cannon lide 25 which is based on plustek back-ends. I have an intuition that plustek will be more friendly with FreeBSD.