As for modprobe, all the modules (aka drivers) are compiled statically... So in a sense you have one big kernel file, rather than a small kernel but with multiple drivers as .ko files sitting in the file system. A static (or mostly static) kernel seems to sound better. So it seems to have a driver built right into the kernel has that little bit extra advantage when compared to runing as a module.
The problem with this is the myraid of problems with driver support - as you can see first hand :(
This is one of the biggest hurdle to people using Snakeoil, something I will hopefully address eventually. In the mean time, I appreciate your patience getting this to work. :) Let me know how it goes with that kernel. Hoping with a working Internet, the installer will be able to download the right GRUB boot loader, so you don't have to run boot repair (In theory you only need to do this if you're using EFI). I believe EFI with CSM configured will still use the EFI grub boot-loader. I boot in BIOS so don't have this problem.