I believe the new build works with the Alpha Wheels, it does on my system, but I haven't heard back from anyone using R3 and the Alpha Wheels together. If you are planning on using it, I'll make sure it works, I just might need some feedback from you.
I'm also going to be releasing pre-made scenes just for people who want to practice camera moves with the Alpha Wheels. I just need to scan some more people and locations and we'll be good to go. I couldn't legally redistribute Fuse characters or other people's scans, but I've started scanning my own people now.
I have that same MBP with the 750M. That sadly doesn't work with Redshift. That GPU is too old and the architecture isn't supported. At least from reports of other users who have it, I haven't even tried personally.
To start, you will probably feel more comfortable using Physical, it looks "normal" in the viewport and will run "fine" on your MBP. So get C4D Broadcast and you'll be fine as your learn the system. There is a considerable amount of work that can be done with the lights off, aka just for blocking in relation to the set.
Moving forward however, I would heavily recommend leaving the Apple ecosystem and getting an MSI/HP laptop with an Nvidia 1060 or higher inside of it. Your Adobe apps will run faster and you'll be able to use GPU rendering which is 100x faster and more fun to use.
If you don't want to leave the Mac eco system High Sierra allow for external GPU enclosures but then you have to lug an eGPU on set, on scouts, etc. Compared to a modern MSI laptop just has it inside of it.
On top of that, if you want to get into Reality Capture (photo scanning, LIDAR, etc.) which essentially allows you to automate creating 3D models from the real world, that is also a PC only process. It sounds complicated at first, but I'll make videos soon showing how you can get a 3D model of a building or prop using only your phone.
For the future future, I'm building out a new project in the background that uses game engines and the potential of VR/AR is always there, although I'm not specifically building for that. If you ever want to use a Rift, VivePro, MagicLeap (AR), headset for this type of work, you want to go PC and Nvidia.
I don't believe Apple will catch up, unless something truly drastic changes. I'd be happy if they start supporting Nvidia again or if Unity/Unreal/Octane/Redshift start supporting Metal/AMD. But this is the current eco system for 3D.