No, Docker usually drops CAP_NET_RAW within the container. But you can change that and other container technologies definitely keep CAP_NET_RAW within the container.
The majority of OpenWRT/LEDE patches are gross hacks that need a major rework or a completely different approach.
This is not the first patch of that kind.
Sadly, the author failed to read on the history of kdbus and AF_BUS.
Just using UNIX domain socks is not the solution. This is more or less what dbus currently does and has major issues with memory accounting and trusts.
This does not make any sense.
As soon you issue any system call you will trigger a context switch.
So, eve without using FUSE and just using LKL as tool to extract your favorite filesystem it will face them.
But the context switches not the bottleneck in FUSE.
Did you benchmark?