[racket] using packages from Planet

Hello friends,

first of all sorry for my trivial questions, but all the stuff is pretty new to me.

I have download today the package with the line(in DrRacket 5.3):
(require (planet orseau/mred-designer:3:8))
Questions:
1):Is this designer the default designer to use for rapid gui development?
2):Do I have to type always the line :
(require (planet orseau/mred-designer:3:8)) to start the designer?
3):When I eval the line to start the Designer from MzCOM I get an error:
Racket error: default-module-name-resolver: the kernel's resolver works only on `quote' forms given: '(lib "planet/resolver.rkt").

Yours,