curve alias parametric and a sphere should be a sphere

dear group,

working with package DRAW.lisp I have 3 questions.

[1]
I learned form Mario the construction (%i2):

(%i1)  line : [2,3,0]+t*[1,-2,1]$
(%i2)  draw3d( apply(parametric,append(line,[t,-2,2])));

I abstracted this construction to

(%i3)  Line(L,T) := apply(parametric,append(L,T));
(%i4)  draw3d(Line(line,[t,-2,2]));

ok. But I don't like to do this definition everytime I use draw ..
ok, I could write all private function definitions in a seperate file and load it
everytime,
but better: how to formulate (%i3) in Lisp in order to put it in DRAW.lisp? 

[2]

I prefer the identifier 'curve'   to 'parametric'
and      the identifier 'surface' to 'parametric_surface'.
So currently I do everytime:

(%i5)  alias(curve,parametric,  surface,parametric_surface);
(%i6)  draw2d(curve(cos(t),sin(t),t,0,2*%pi))$

how to formulate (%i5) in Lisp in order to put it in DRAW.lisp? 

[3]

The grafic output of the sphere (%i6) looks elliptic.
As a work around I shorten the gnuplot window by hand, so that (%i6) looks spherical :)
Is there a possibility to set the aspect ratio, so that 'a sphere looks like a sphere'?
Or is there an plot option like maple's 'scaling=constrained'?

HTH Wolfgang