10k for pull up external.
i have only two wires to tie at right and two wires to tie ar left of steering wheel.
So 12 buttons in fact .
If i tie like the thread you provided , so many wires and this is the first part of entire PIC system .
i am not sure there are enough wires after this.
I have 25 inputs/outpouts tie to PIC .(without components reserved operation )
Perhaps the eight outpouts/input reserved to LCD (for test before FIS tachometer connected) .