Re: 3rd Call: HowTo make a 100% sheet with a hole in it that reveals a link

Well, 

a circular hole indeed either requires the elliptical arc command
from the full profile or some numerial approximation to an elliptical
arc using cubic beziers with the tiny profile, not really a problem 
for practical purposes (I already did some numerics for this 
using a simple PHP-script).
Of course then the preserveAspectRatio should not be none (and
the top path has to cover a very large area outside the
viewBox for decorative purposes). But all these variants are not
very tricky and are straight forward.