After installing (well extracting and attempting to run) the linux version of Navicat 8, I found it's simply the Windows version wrapped in wine. I say attempting, because every attempt failed. Probably because I am using x86_64 bit 2.6 kernel.
I successfully installed the Windows version in CrossOver Pro 6.2, and only found 1 bug so far. When you change databases and collapse the previous one without double clicking (instead clicking the expand/collapse tree icon [+/-]), it does not redraw the screen properly. I am checking all the settings and will post if I find a work-around.