Please ignore any questions answered by 4.4BSD book

i would be surprised if either of these topics were in the 4.4 book
as they are not part of 4.4BSD.
   
   Likewise, what is the interface to LKMs?

it is based on the sunos modload.

   Are we susceptible to the same attacks SunOS is, in that hackers can load
   a stealth-module?

what do you mean by `stealth-module' ?  netbsd only allows LKM
operations when the system is in insecure mode (securelevel < 1).

   What kind of kernel functionality can be modified by an LKM?

device drivers, system calls and file systems, i believe.  look
in /usr/share/lkm for examples.

.mrg.