The version number is on the "Internal" Tab, you can also select the number of threads/processors working on any project there too, the default is Max detected on your computer. If you have the Voxel option it shouldn't be a very old version the latest is v1.7.9.1

I use a PC, an old one at that but I know many others at FractalForums that use MAC without any problems at all, I think most of them run MB3D under WINE but don't know for sure, my suggestion for Problems running on a MAC is to go here at FractalForums and start a New Thread asking for Help running MB3D on a MAC, you'll get a good response, everyone is very helpful there.

http://www.fractalforums.com/mandelbulb-3d/

As far as operating a fully functional version ask away.

Remember...No matter where you go there you are