Is it possible to clear jelly effect of the windows?
I can? Remove top and bottom bars to install windows decorator and cairo dock?
What is the current resource consumption has improved in this regard?
Is it stable KDE Sabayon?
answers to all your questions:
Yes do, jelly windows possible. Working in Kwin (KDE 3D Effects). Also Compiz works in KDE, less good that it works in XFCE, LXDE or MATE. Compiz works Bad in GNOME3 and in Cinnamon, but Works good in XFCE, LXDE and MATE. Not works in E17 or Flux.
Remove panels for use Cairo-Dock, AWN or Superkaramba, yes possible!. For similar packages as, Desklets or GDesklets (for GNOME) i not tested then with KDE, but they working in MATE and GNOME2.
resource consumption is somewhat high in KDE, but depends of you configuration.
I use Sabayon 6 years ago. I use all Graphical env, mainly i use KDE. For me, KDE are the most stable Sabayon spins. Including, it is experienced with this since all the antique sabayons were KDE Centric!