Hi Phestus,
I have used BB with bootcamp on a macbook air - it worked fine though you have to open a choice between
mac and bootcamp every time. If you use bootcamp you first have to load windows and then you can install BB. I used it on the macbook air for live gigs( I sing a Gospel Hour at various age care places) and found it ok as i mainly opened it up in bootcamp.

I then used a program called 'Parallels' which enables you to vary the size of the partition without any problems - so I deleted the bootcamp from the laptop - but you still have to install windows and then BB. It's costly but there is no other way out.
The same goes for your iMac.

I have an iMac 27" for a desktop and have Parallels installed with windows 10 and BB 2016 for windows - the two systems Mac and Parallels work well together.

For gigs I have a new acer i7 with windows 10 because originally I bought the BB mac version for the Macbook air but found it to be full of glitches - especially words disappearing .
I have also the BB Mac version on the iMac but I still think the windows version is far better.

Hope this of some help
Cheers
Ivan