Good stuff Jeff! Looking forward to part 3.
Yes, but an EF-M mount won't work with a speedbooster, isn't that what you were wanting to do with it?
Personally, I would steer clear of a text msg campaign. Text is very invasive and could hurt your progress as much as it helps. It feels to the consumer like a commercial invasion of their private space. Hence it is rarely used in serious, well informed marketing campaigns.
"Don't wear pants" is pretty much the best advice that could ever be given for any activity in life.
A 10mm on a full frame camera would be 10mm. No negative crop factor. A 10mm on a GH4 in 4K mode is ~23mm.
You can only get the Rokinon 12mm in MFT, EF-M, or Sony E mount - none of which are compatible with Speedbooster. I have the 12mm in MFT mount, and for cinema applications, I can't imagine ever needing anything wider.