thanks for the replies
installind, from what i observed while installing the motherboard, none of the screw points are non-metalized. and i got only 4 mounting points(elevated) that matched with the board. If i set some standoffs there will be a problem with tho I/O panel when installing.
taking obsolete99's idea, if i put electrical tape, even then it is not rendered safe. as after making holes in the electrical tape i have to insert a screw that screws in with the metalized cabinet plate, thus grounding it.
There is no place to insert a standoff as far as i could see.