The Integration Designer works on the Mac, but there are some rendering issues that I have noticed - although I haven't got to the bottom of what's causing it.
I just checked the preferences on my own Mac, and you are absolutely right - that preference is missing. This is a bug, and I'll make a JIRA for it once I do a clean setup here and investigate a bit further.
If you fast-forward to the Running EIPs and Camel Configurations section in the online help, then you will see instructions on how to run a route. If you don't have the FUSE MR location set, then you should see some red text asking you to please set the location. If you click on this text (it's a link) it should bring you to the FUSE MR configuration page.
Let me know if this works for you!
I guess this issue still persists even with FID 1.2.1.