WOW, OK Pavroo. It worked. Did this:
1- From lxqt session did a apt-get update, and after apt-get dist-upgrade
2- rebooted
3- arrrrghhhhh, system rebooted to a terminal interface, went with startx, something mixed like a hibrid lxqt/xfce showed up
4- Used an sparky "system upgrade tool" that I found in the hybrid
5- Closed session to the same terminal, went start x again
6- ran terminal and did apt-get install sparky-desktop kde
7- rebooted in to lxqt

it worked as expected fiuuuuuuu
8- log off, log in to plasma it WORKS, ALL my preferences are there. DONT KNOW WHAT version of kde/plasma it is (is there any way to find out???)
Well, after scare, it seems it IS working. ANY ideas, suggestions, etc will be WELCOME