I'm certainly open to suggestions.  This was one of those one-hour hacks I
had to make to get my machine usable for a trip, and wasn't very well
thought out.  I agree that your solution number 3 is best.

   - I can understand why you want to take out RTM_LLINFO routes, but
  why RTM_STATIC?  Do you have any routes which are RTM_STATIC but which
  *aren't* also RTM_GATEWAY or RTM_LLINFO?

I don't remember, but is there any reason not to flush these?